PURPOSE: To prevent interruption from a different job except for a self job into a file and to prevent an errorneous processing accompanied with data update by means of the different job by excluding/releasing the file in a job unit.

CONSTITUTION: A user starts a job S1 and a job exclusive control means S2 gives the registration request of the file to a job exclusive control management table S7. Thus, the job exclusive control management table S7 is retrieved and whether the file is allocated by the other job is inspected. When it is not allocated, a file name and a job occurrence number are registered in the job exclusive control means S2. A job step initialization means S3 executes a processing before the execution of a first job step S4. When the job terminates, a job termination means S6 eliminates registration executed on the job exclusive control management table S7, and the different job can allocate the file.