PURPOSE: To attain the effective application of a data base, the record, etc. by detecting automatically a registered terminal which is not used yet and releasing the resources used by said terminal.

CONSTITUTION: A terminal service program sets a terminal control table flag 1 prior to the terminal service processing 9 to display a busy state of a terminal. A mobile monitor program is started every fixed period of time to check the flag value of the terminal control table for all terminals registered. Then the deletion is requested to a terminal control program for a non-working terminal having the flag value "0". Thus the registration is automatically deleted for a terminal that is not used for a fixed period of time or longer. This ensures the effective use of terminal resources.