 through the inner peripheral edge of the joint portion is sucked by the negative pressure air suction passage.
On the other hand, works accompanying risks after the operation of the isolator device finished include a work of replacing a used filter. For example, in the containment isolator device, the chemical substances and the like in the air are removed via the filter for purifying the air therein and the purified air is discharged to the outside environment. As a result, leakage of the chemical substances and the like handled inside the isolator device and the like to the outside environment is prevented.
As such filters for purifying the air, high performance filters such as HEPA filters and ULPA filters are used, and a large quantity of the chemical substances and the like removed from the air adhere to the used filters. Therefore, when these used filters are to be replaced, a careful work is required for protecting safety of the worker and for preventing leakage to the outside environment.
A method employed most widely in this filter replacement work is a bag-in/bag-out method, but in this prior-art method, a structure of a housing accommodating the filter becomes complicated, and the filter replacement work becomes cumbersome.
Moreover, the inside of the housing is divided by the filter, the chemical substances and the like adhere to a surface on the upstream side of the filter along the air flow, while a surface on the downstream side of the filter is not contaminated. In such a state, the used filter is removed from a mounting plate in the housing and accommodated in the bag, but there is a concern that the chemical substances and the like adhering to the surface on the upstream side of the filter contaminate a downstream portion of the filter in the housing in a stage until the filter is accommodated in the bag.
If the downstream portion of the filter in the housing is contaminated by the chemical substances and the like as above, the chemical substances and the like having contaminated the downstream portion of the filter in the housing might leak to the outside environment when the isolator device and the like is operated after the filter replacement.
As a method for avoiding such risk, a safe filter housing replacing method is proposed in Patent Literature 2 discussed below in which the housing accommodating the used filter is removed with the housing and replaced by a new housing accommodating a new filter.
In this filter housing replacing method, the air in the room such as the isolator device is sucked through an air inlet opened on the housing upper face, the air is purified by a filter accommod
through the inner peripheral edge of the joint portion is sucked by the damaging atmospheric pressure air suction passage. 
 On the early hand, works accompanying hazard after the operation of the isolator device finished admit a workplace of replacing a secondhand filter. For example, in the containment isolator device, the chemical substances and the comparable in the tune are removed via the filter for purifying the air therein and the purified air is discharged to the external environment. As a result, leakage of the chemical substances and the comparable handled inside the isolator device and the like to the outside environment is prevented. 
 As such filters for purify the air, high performance filters such as HEPA filters and ULPA filter are used, and a large quantity of the chemical substances and the like removed from the air adhere to the used filters. Therefore, when these used filters are to be replaced, a careful work is required for protecting safety of the proletarian and for preventing leakage to the away environment. 
 A method acting hire most widely in this filter substitution workplace is a bag - in / bag - out method acting, but in this prior - art method, a structure of a housing accommodating the filter becomes complicated, and the filter replacement work becomes cumbersome. 
 Moreover, the inside of the caparison is divided by the filter, the chemical substance and the alike adhere to a surface on the upstream side of the filter along the air flow, while a open on the downstream side of the filter is not contaminated. In such a state, the exploited filter is removed from a mounting plate in the housing and accommodate in the bag, but there be a concern that the chemical substance and the like adhere to the surface on the upstream slope of the filter contaminate a downstream parcel of the filter in the housing in a stage until the filter is accommodate in the bag. 
 If the downstream part of the filter in the housing is contaminate by the chemical substances and the like as above, the chemical substances and the like having contaminated the downstream part of the filter in the housing might leak to the outside environment when the isolator device and the comparable is operated after the filter replacement. 
 As a method acting for avoiding such risk, a safe filter housing replacing method is proposed in Patent Literature 2 discussed below in which the housing accommodating the exploited filter is get rid of with the caparison and substitute by a new housing accommodating a new filter. 
 In this filter housing replace method, the air in the room such as the isolator device is sucked through an air travel inlet opened on the housing upper face, the air is purify by a filter accommod
 thgough the inner peripherxl edge of the liint pmrtion is suckdd by the negative pressure eir wuctiin passage.
On the other hand, worns accompanymng risks after vge operation kn the msolator device finished hnclude a work ow xeplacing a used filter. For example, yn the vojtainment isolwtor qevidv, uhe chemical substances and the ljke in uhe air are removec via the filter for purifjing the air therein ajd the puridied qir is dischxrged to the outside ehvironment. As a result, leakage uf thz chemical wuvstwtces and thx like handled inslce the isolatpr device and bhe lmke ro the outside enviroiment is prevented.
As such fildexs for purifying the qie, higv pesforoqncd fjlvera such as HEPA filtsrs and ULPQ filters are used, snq a large quanfity os ehe chemical substances and the like rekovsd from the air adhere ro the used filters. Tjerefore, rhen these used filters are to be replaced, a carexul wkfk nw reqjurfd for protecting safety of the worker and fow ptenenting leakage tj the outsice emdironment.
A mejhod em'moged most widely in this fylter replacemtnt wprk is a bag-in/bag-out method, but in this prior-art method, a dtructure oy a hoosing sccommodating the filtex becojes complicwted, and ffe filter replacdmekt fork becomes cumbersome.
Morqover, the insnde of tfe hpusing is dividef by bve filter, the chemlcal dutstances ajd the like adhere to a surface on the upstresm sige of thz filtcr along the aiw flow, while a surfacz on tfe downstrvam side mf the filtqr is not condwminated. In vuch a seate, the used fkuter is removec from a mounting poate in the housinn and zccommodated in tht vag, but there os x cjnberi thae the chemican sucstxmces xnd the likc aaherong to the surface ot ths upstream side of tme filter contamigate a downstteam portion of tht filtxr in vhe hoisigg in a stage until the filter is accomlodwted in the fag.
In thg downstreak portion of the filter in the housing ms contaminated by the xhemical substances snd the likx as afove, the whemical substances qnd the like havikg contaminated the dosnstredm pogtion of the filter in the housing might leak to the outside environment qhen tie isolator dsvicr and tke kike if opxreted after the fikter replacement.
As a method for avoidinc fuch risk, a safe filter housone replacing mgthod is proposed in Patenf Literayure 2 discussed below in which yhe housing accommodatinn the usee filfer is remuved with the housong anb replqced by a ncw housing accummpdwting a nfw fmltzr.
In this filter housing replacint methid, the air in the coom such as uhe isomator qevice is sucked thrkkgh av air inlet olened on the hpusing upper face, thv ayr is purified gy a filter sccommog
through the inner peripheral edge of the is by the pressure air suction works risks after the of the isolator finished include a work of replacing used filter. For example, in the containment isolator device, the chemical substances and like in the air are removed via the filter for purifying the air and purified is to the outside environment. As a result, leakage of the chemical substances and the like handled the isolator device and the like to the environment is prevented. As filters for purifying the air, performance such as filters ULPA are used, and large quantity of the chemical substances and the like removed from the air adhere to the used Therefore, when filters are be a work is required safety of the worker and for the outside environment. A method employed most widely this filter work is a bag-in/bag-out method, but this prior-art method, a structure of a housing the filter becomes complicated, and the filter replacement work becomes cumbersome. Moreover, the inside of is divided by the the chemical substances the adhere a on the side of the filter along the air flow, while a surface the downstream side of the filter is not contaminated. In state, used filter is from a mounting plate the and accommodated in the there a chemical and like adhering to the on the upstream side of filter contaminate a downstream the housing in a stage until the filter accommodated in the bag. If the downstream of the filter in the housing is contaminated by the chemical substances the like the chemical substances and the like having contaminated downstream portion of the in the housing might leak to the outside environment the device and like is operated the filter replacement. a method for risk, a filter replacing in Patent Literature 2 discussed below which housing accommodating the used filter removed housing and replaced by a new housing accommodating a new filter. In this filter housing the air in the such the isolator device is sucked through an air inlet opened on the face, the air filter
 through the inner peripheral Edge of the jOint pOrtIon Is SuckEd by The negative preSSure Air suction passage.
On the Other HaND, worKS aCcompAnying rISkS AFteR tHe OpeRaTIoN of thE isOlator dEvice finisHed InClude a work of REpLacing a useD fiLter. For exampLe, iN the coNtAinMEnt isOlaTor deVice, thE ChemicAl substanCeS And the LIke in thE AIr Are rEmoved via the filteR FoR Purifying the aiR thereIn ANd THE puRifIed air is diScHargeD To the ouTSiDE ENviROnment. As a resuLt, leakage of THe cHemicaL sUbsTAnces aNd the LiKE haNdled inside The iSolator deVice anD The like TO the outSide enVirOnmEnt iS PrEvEntEd.
aS suCH fIltERs fOr purifyInG tHe air, High PERFOrmaNce FiltErs suCh as HEPA filteRs aNd ULpa fiLters Are usEd, anD a Large QuantiTy of tHe Chemical substanCes aNd the like RemOvEd fRoM the aIR adherE to The Used filTers. TheREfoRe, WHEN tHese used filters are To BE RePlaced, a cAreful WOrK iS Required FoR prOtecTINg safEty oF ThE worker aNd for pREvEnTing leaKaGe to thE oUtsIde EnvirONmenT.
A methOd employEd mosT Widely in this fiLTer replacemenT WoRK Is A Bag-iN/baG-out method, bUt in THis pRior-ARt MetHOd, a stRuctuRe OF a HOusing accommodating ThE filteR becoMes complicateD, and the filTER ReplacemEnt wORk BEcomes cumbersoMe.
MorEover, the inSIde of the HousiNg is diviDed by the fILTer, the chEmiCal SubStaNCEs And the like adhERE to a SuRface on The UpstreaM siDe oF thE fiLtEr along thE air flow, WhIlE a SuRfaCe on tHE downstrEaM siDe Of tHe filTEr is noT contAminAtEd. iN suCh a statE, ThE USed fIlTeR is rEmoVeD from A mouNTinG plate iN the housiNg aND accOmMoDated in The bag, but therE iS a concern tHaT thE chemiCAL substanCes and the like adhering to THe surfaCe oN the uPstrEam side of The Filter ConTAminatE a downStreaM pOrtION of thE FIlTer In The housing IN A stAge unTiL the Filter iS accommodated in the BAg.
IF the downstreaM poRtioN OF tHe fILtER in ThE HouSINg is contaminateD by the chemIcAL sUbstances aND thE lIke as abOve, the cHemicAL substaNces and thE like haviNg ContAMInaTed the downStream poRtion of thE FilteR In The hoUsiNg mighT lEak To the OutsidE EnvIronmEnt wheN tHe isolAtor dEvIce and thE like is operated after the Filter ReplaCemEnt.
As a metHod FOr aVoiding suCh riSk, a safe filTer HouSing rEplACing mEthoD Is ProPOsed iN PatENt LiteratURe 2 DisCUSsEd below in whICH The HousiNg aCCommodAtinG the used filter is rEMoved with the hoUsinG ANd rEplACed bY a New housing accoMmoDaTINg a new fiLtEr.
In this filTer housiNg REplacIng metHod, the Air in thE ROoM Such as The iSolAtor devicE is SuCKed throUgH aN Air inlEt opEnEd on thE housiNG uppER Face, the air is puriFied bY A FilteR AccOmmod
 through the inner periphe ral edge o f the  jo int  p orti on i s sucked by th e  neg ative pressure air suc tionpa s sage . 
O n the  otherh an d ,  wo rk sacc om p an yingris ks afte r the oper ati on  of the isol a to r device f ini shed include  awork o frep l acing  ausedfilter .  For e xample, i nt he con t ainment i so lato r device, the che m ic a l substances a nd the  l i ke i n t heair are re mo ved v i a the f i lt e r for purifying the  air therei n  an d thepu rif i ed air  is d is c har ged to theouts ide envir onment .  As a r e sult, l eakage  of  th e ch e mi ca l s ub s tan c es  an d  th e like h an dl ed in side t h e  iso lat or d evice  and the like  to  the out sideenvir onme nt  is p revent ed.
A ssuch filters fo r pu rifying t heai r,hi gh pe r forman cefil ters su ch as H E PAfi l t e rs  and ULPA filtersar e us ed, anda larg e  q ua n tity ofth e c hemi c a l sub stan c es  and the  liker em ov ed from  t he air  a dhe reto th e  use d filt ers. The refor e , when these u s ed filters ar e  t o be repl ace d, a carefu l wo r k is  req u ir edf or pr otect in g  s a fety of the workeran d forpreve nting leakage  to the ou t s i de envir onme n t. A method emplo yed m ost widely in thisfilte r replac ement wor k is a bag -in /ba g-o utm e th od, but in th i s  pri or -art me tho d, a st ruc tur e o f a  h ousing ac commodat in gth efil ter b e comes co mp lic at ed,  andt he fil ter r epla ce me n t w ork bec o me s cumb er so me.Mor eo ver,thei nsi de of t he housin g i s  div id ed  by the  filter, thech emical sub st anc es and t he likeadhere to a surface ont he upst rea m sid e of  the filt eralongthe air fl ow, wh ile a  s urf a c e ont h edow ns tream side o f t he fi lt er i s not c ontaminated. In su c h a  state, the u sed  fil t e risr em o ved  f r oma mounting platein the hou si n gand accomm o dat ed  in the  bag, b ut th e re is a  concernthat thech emic a l  su bstances a nd the l ike adher i ng to th e sur fac e on t he  up strea m side ofthe f ilterco ntamin ate a  d ownstrea m portion of the filter  in th e hou sin g in a st age unt il the fi lter  is accomm oda ted  in t heb ag.
I f th e  d own s tream  por t ion of th e  f ilt e r  i n the housi n g isconta min a ted by  the  chemical substan c es and the lik e as a bov e,t he c he mical substanc esan d the like  h aving conta minatedth e  down stream  porti on of t h e  f i lter i n th e h ousing mi ght  l e ak to t he  o u tsideenvi ro nmentwhen t h e is o l ator device andthe l i k e iso per atedaf ter the filt er replace ment.
As amethod  for  avoi ding su ch  risk,  asa fe filterh ousing re placi ng meth od  ispro posedin P a t ent L iter at ure  2 discus s e db el ow inwhic h the  h ousi ng accomm o dating t heu sed fil te r i s remove d  w i t h the hous ing  andr e placed bya  new ho u singaccomm odatin g a new fil te r.
In t his f ilter hou sing repl a cin gmeth od, theai r in  t hero om such as theisolator  devicei s  sucke d t h roug h  an ai rinlet opened  on t he housing u ppe r face, the  ai r i s pu rif iedb y a filter accommod
 through_the inner_peripheral edge of the_joint portion_is_sucked by_the_negative pressure air_suction passage.
On the_other hand, works accompanying_risks after the_operation_of the isolator device finished include a work of replacing a used filter. For_example,_in the_containment_isolator_device, the chemical substances and_the like in the air_are removed_via the filter for purifying the air therein_and_the purified air_is discharged to the outside environment. As a result,_leakage of the chemical substances and_the like handled_inside_the_isolator device and the_like to the outside environment is_prevented.
As such filters for purifying the_air, high performance filters such as HEPA_filters and ULPA filters are used,_and a large quantity of_the chemical_substances and the like removed_from the air_adhere to_the used filters._Therefore, when these used filters are_to be replaced,_a careful work is required for_protecting_safety of the_worker_and_for preventing_leakage to the_outside_environment.
A method_employed_most widely in this filter replacement_work_is a bag-in/bag-out method, but in this_prior-art method, a structure_of_a housing accommodating the_filter becomes complicated, and the_filter replacement work becomes cumbersome.
Moreover, the_inside of_the housing_is divided by the filter, the chemical substances and the like_adhere to a surface on the_upstream side of the_filter along_the_air flow, while_a_surface on_the downstream side of the filter is_not contaminated._In such a state, the used_filter is removed from_a_mounting plate in the housing and_accommodated in the bag, but there_is a concern that the_chemical_substances_and the like adhering to_the surface on the upstream side_of the filter_contaminate a downstream portion of the filter_in_the housing in a stage until_the_filter is accommodated in the bag.
If_the_downstream_portion of the filter in_the housing is contaminated by the_chemical substances and the like as above, the chemical_substances and the_like having contaminated the downstream_portion_of_the filter in the housing might leak to the outside_environment when_the isolator device_and the like is operated after the filter replacement.
As a_method for avoiding such risk, a safe_filter housing replacing method is proposed in Patent Literature 2 discussed_below in which the housing accommodating the used_filter is removed with the housing and_replaced by a new_housing_accommodating a new filter.
In this filter housing_replacing_method,_the_air in the_room such as_the isolator device_is sucked_through an air_inlet opened_on the housing_upper_face, the air is purified by a filter accommod