12. The document control method according to claim 9 , further comprising: a user information storing step of storing information of registered users; a charge information storing step of storing charge information; and a history information storing step of storing information of electronic document access histories.
9. A document control method performed in a document control apparatus for storing and controlling electronic documents accessible from an external apparatus, the method comprising: a storage device a registering step of registering at least one electronic document to the storage device, the electronic document being transmitted from the external apparatus; a period controlling step of storing information of a document control period of the electronic document registered in said registering step; a keeping step of keeping the electronic document in the storage device even after the document control period of the electronic document has expired; an access prohibiting step of prohibiting access from the external apparatus to the electronic document whose document control period has expired; a first confirming step of confirming whether or not the document control period may be extended when the document control period has expired; a second confirming step of confirming whether or not a user requests temporary access to the electronic document with an additional charge, when said first confirming step confirms that the control period may not be extended; a temporary access allowing step of allowing temporary access to the electronic document whose document control period has expired when the additional charge has been confirmed for the temporary access to the electronic document, when said second confirming step confirms that the user requests the temporary access to the electronic document with the additional charge; and a transferring step of transferring the electronic document to the external apparatus based on a user request, when said first confirming step confirms that the control period may be extended, or when said temporary access allowing step allows the temporary access to the electronic document.