6. The document control apparatus according to claim 1 , wherein said keeping means keeps an electronic document that is frequently accessed from the external apparatus, and wherein said temporary access allowing means allows the temporary access to the stored electronic document based on the predetermined charge.
1. A document control apparatus for storing and controlling electronic documents accessible from an external apparatus, comprising: a storage device registering means for registering at least one electronic document to the storage device, the electronic document being transmitted from the external apparatus; period controlling means for storing information of a document control period of the electronic document registered by said registering means; keeping means for keeping the electronic document in the storage device even after the document control period of the electronic document has expired; access prohibiting means for prohibiting access from the external apparatus to the electronic document whose document control period has expired; first confirming means for confirming whether or not the document control period may be extended when the document control period has expired; second confirming means for confirming whether or not a user requests temporary access to the electronic document with an additional charge, when said first confirming means confirms that the control period may not be extended; temporary access allowing means for 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 means confirms that the user requests the temporary access to the electronic document with the additional charge; and transferring means for transferring the electronic document to the external apparatus based on a user request, when said first confirming means confirms that the control period may be extended, or when said temporary access allowing means allows the temporary access to the electronic document.