Patent ID: 8159326

Claim:
A locking device for locking/unlocking a lock of a door of a closed space, comprising: a first transmission antenna for transmitting a first signal to a range including outside of the closed space; a second transmission antenna for transmitting a second signal to an inside of the closed space as a target; a key which transmits a first response signal when receiving the first signal and not receiving the second signal, and transmits a second response signal when receiving the first signal and also receiving the second signal; a reception antenna for receiving at least the first response signal from the key; and a control unit for controlling whether locking/unlocking can be performed on the lock or not, based at least on whether the reception antenna receives the first response signal or not wherein in a case where the reception antenna receives the first response signal from the key, the control unit controls the first transmission antenna to transmit an individual authentication ringing signal and controls the second transmission antenna to transmit a third signal before the first transmission antenna transmits the individual authentication ringing signal, the key transmits a first individual authentication response signal as a response to the individual authentication ringing signal in a case where the third signal is not received, and transmits a second individual authentication response signal as a response to the individual authentication ringing signal in a case where the third signal is received, and the control unit controls the lock so that locking/unlocking of the lock becomes possible only in a case where the key transmits the first individual authentication response signal to the reception antenna as a response to the individual authentication ringing signal.