PURPOSE: To park an entering vehicle in a designated parking lot by recognizing that a parking lot corresponding to entrance control release information recorded on an issued key is in the parking state and recognizing that a parking lot corresponding to entrance control release information recorded on a returned key is in the empty state.

CONSTITUTION: A key 6 from a key issue device 5 is transferred to the driver of a vehicle 7A, and a computer 4 for management updates the address in a stored map, which corresponds to the parking lot designated by the issued key 6, from the empty state to the parking state. When a vehicle 7B approaches a parking lot, the signal transmitted from the key 6 is received by the receiver of a controller 9, and a control plate falls under the floor so that the vehicle can enter the parking lot. Meanwhile, when a vehicle 7D goes out of a parking lot and arrives at an exit 1B, the signal from the key 6 is received by a leaving sensor 10, and the computer 4 for management updates the address in the stored map, which corresponds to entrance control release information stored in the returned key 6, from the parking state to the empty state.