To realize usage preservation for a facility and the like available from a remote location such as a service facility by means of radio communication and operable effectively against fluctuation in the number of users of the facility.

Reservation is managed by comparing and referring the number of persons and the time for reservation of an attraction facility inputted from a personal digital assistant 1 with a reservation list 3a managed by a host device 3 and guiding a series of reservation numbers and their usage prediction times with respect to the reservation from the personal digital assistant 1. The host device 3 grips location of the personal digital assistant 1 inside the theme park from the installation area of a radio base station 2 communicating with the personal digital assistant 1 and predicts execution of the reservation to reconfirm or change the reservation for performing a smooth reservation service even if the number of facility users is fluctuated.