To safely distribute a file distributed within a specific organization, into the other organizations.

When a capsulated file is opened on the Internet, an open file management server 30 in the Internet is instructed to open the capsulated file and made to capsulate the capsulated file, with an intra-company file management server 10 in an intra-net as a window. During submission processing of restoring the open capsulated file to the capsulated file distributed only within the intra-net, the open file management server 30 is instructed to decode the open capsulated file, with the intra-company file management server 10 as a window, and the capsulated file is generated. In this case, a relation between the open capsulated file and the original capsulated file before opening is stored, and in the capsulated file after the submission, the same ID and access right as the original capsulated file are maintained, so that the transition after opening of the open capsulated file can be confirmed.