To make it possible to monitor file transfer, by synchronizing the transfer with the opposite side and recording the monitor result, etc., of the transfer state at the time of file transmission and reception, expanding received data in an operation data base, and sending data in the operation data base to the opposite side at a request.

After file reception ends, a data base expanding process start device 5 expands the received file in the operation data base. When data are copied from the operation data base to a transmit file, a transmission controller 3 confirms whether or not it can be transmitted and informs of a transmission device 6, which starts a file transfer tool to transmit the file. After the file transfer, an end controller 7 confirms the transmission state and in case of an abnormal end, a retransmission controller 8 performs a transmitting process until the file transmission normally ends. A transfer history reference device 9 writes the file reception/transmission state in a history file and displays the transfer history.