Various settings are stored into a setting storage table for stop-key processing. These settings are related to a job kind where an operation is stopped by manipulating a stop key, a job kind where an operation is made to pause, and a job kind where an operation is continued without any interruption. When the stop key is manipulated, the job set to the stop operation is directly stopped, and the job set to the execution continuation is continuously executed. The jobs set to the pausing operations are displayed in a list. These jobs are selected one by one, or in a batch mode. Thereafter, either the stop operation or the restart operation is instructed. Accordingly, even under such an environment that a plurality of jobs are executed in a parallel manner; a desirable job can be quickly stopped, and moreover, lowering of throughputs of other jobs can be suppressed.