PURPOSE: To make it possible to easily know the period in which maintenance operation should be done by providing a means which displays the total number of recording media that the processor processed in the past by the insertion of a recording medium where a specific information is recorded.

CONSTITUTION: When the card C where the specific information prepared to perform maintenance operation is stored is inserted into the processor, a read and write part 8 reads information out of the card C and sends it to a main control part 20 after the number of inserted cards is displayed. The main control part 20 when judging that the received information shows the storage of a specific information instructing to display the cumulative process number of the card, reads the contents of a cumulative process number counter provided in a specific area of a storage part 21 and displays them at a display part 3. Consequently, a customer engineer can judge whether or not the maintenance operation should be done.