A self-diagnosis function is used to acquire information showing the state of deterioration of a hard disk device, and when the hard disk device is deteriorated, a job is executed under the control which is different from that in the case where the hard disk device is not deteriorated. For example, copying job is executed in the HDD use mode in the case of non-deterioration, and copying job is executed in the HDD non-use mode (an image memory is used) in the case of deterioration. Further, the number of retrials by an alternative sector in the case of occurrence of errors of writing in a hard disk device in the course of job execution is changed according to the state of the deterioration.