To improve service and to acquire many users of a hotel by enabling special service for a member as saving manpower of a front job in the hotel.

A new room key card is not issued for the user of the hotel having a member's card and whose reservation of stay is completed based on a member's number by a card issuing machine 15 and the member's card is used as the room key card. Then, when the member's card is inserted into an automatic check-in/check-out device 21, a reception work to return the member's card to the user after it is rewritten to a condition effective as a room key by referring to reservation information and customer information based on the member's number is performed at the check-in and on the other hand, adjustment work is performed by referring to the customer information based on the member's number at check-out by the automatic check in/check-out device 21.