To facilitate releasing of dead lock state even if a user puts the vehicle in the dead lock state by mistake by a wireless key during riding.

A door ECU 5 locks a door of a vehicle and performs dead locking for keeping the door lock state on determining that lock operation is conducted by a wireless key 1 or a mechanical key 4, and releases the dead lock to unlock the door of the vehicle on determining that unlock operation is conducted by the wireless key 1 or the mechanical key 4 Even if a user puts the vehicle in the dead lock state by mistake by the wireless key 1 during riding, a dead lock release code is transmitted from an immobile ECU 9 to the door ECU 5 to release the dead lock when a regular key used in an anti- theft device for a vehicle is inserted in an ignition key cylinder and it is determined by the immobile ECU 9 that it is the regular key according to code collating.