PURPOSE: To prevent the error of a filing device name between the software of respective tasks and the user of a computer by displaying a logical filing device name which is the identification name specified by the software of the tank during the operation, at respective filing devices.

CONSTITUTION: By connecting to a central processing unit 1 and having an identification name displaying function in addition to a file function, filing devices 3-1-3-N with identification name displaying receive the identification name specified beforehand by respective tasks from the operating system of the central processing unit and display the identification name specified by the task during the operation to display the action condition with a console 2. Namely, by displaying the logical file device name, which is the identification name specified by the software of the task during the operation at respective filing devices, the user can directly visually recognize the logical filing device name. Thus, the error of the filing device name to occur between the software of respective tasks and the user of a computer can be drastically reduced.