PURPOSE: To confirm it during work processing whether cards are continuously set to a card holder or not by answering the presence and absence of the card and the pick-up history of the card to an inquiry from a host device at arbitrary time.

CONSTITUTION: The card present/absent state information of a card holder 3 and the pick-up history of the card are returned corresponding to the inquiry of a host device 5. The card presence/absence information show the presence of the card when the card is inserted to the card holder 3 and show the absence of the card when it is not inserted. For the card pick-up history information, when the card is picked up from the preceding inquiry to this time inquiry, the presence of card pickup is shown and when the card is not picked up, the absence of card pickup is shown. Then, a response is returned to the host device 5. Thus, the control program of the host device 5 can exactly know the state of the card holder 3 at the arbitrary time.