PURPOSE: To improve the response of a document storing/retrieving system at storage of a document by generating a trigger for an index generating request in order to complete the storage processing and generating a document retrieving index in a delay type and an asynchronous type in a different route from the storage processing based on a trigger.

CONSTITUTION: A key word group or a key word group ID group is added to a stored document 1, and the document control information and a document main body are stored in a document control information file 3 by a document store means 2. Then an index generation request of the corresponding document is stacked into a trigger information file 4. Thus the document is stored. An index generation means 5 works when the index generating request is stacked into the file 4. An index key word group ID information file 6 is searched based on a key word group ID and the trigger information of the file 4 for a key word group and a key word group ID group. The keyword group thus obtained and the document are added to the index and the index information is stored in an index information file 7. A document retrieving means 8 searches the file 7 based on a retrieving key word 9 and takes it out as a retrieved document 10.