Abstract: A service change information acquisition program acquires service change information. According to this information, a disclosure scope change program changes the disclosure scope of the document described in document access control information and accumulates it as a disclosure history. A position information acquisition program compares the position information to the former position information. If they are different, the program records a new position, the move-out date, and the move-in date, and accumulates them as a rotation history. An access control program correlates the disclosure history of the document described in the document access information with the rotation history of the person intending access described in the rotation history and allows access to the document which was disclosed while the person intending access belonged to the disclosure department.