PURPOSE: To reduce the communication processing overhead for file access request and file information transfer in each processing node and a file management node and to shorten the time required for access from each processing node to a shared file.

CONSTITUTION: A file management node 61 and processing nodes 111 to 114 are connected to a network B1, and the file management node is provided with the file shared among processing nodes. File information is circulated among the file management node 61 and processing nodes 111 to 114. Each processing node discriminates file information meeting a file access request out of circulated file information based on the file access request from the node and transfers file information to the request source or rewrites contents to relay the file information. The file management node substitutes contents of the file with file information circulated once.