The present invention suppresses rattle and assembly inaccuracies of a magnet and magnet detection sensor, and detects with certainty the position of a lock bolt. The power steering lock unit includes a lock bolt, which is movable between lock and unlock positions, an actuator for causing the lock bolt to move; a transmission mechanism for transmitting the drive force of the actuator to the lock bolt; and position detection sensor for detecting the movement position of the lock bolt. The position detection sensor includes a movable member to which a magnet is fixed, a base plate on which a magnetic detection sensor for detecting the magnetic force of the magnet is disposed, and a holder for movably holding the movable member at a prescribed spacing from the base plate. A linking mechanism is provided for operating the movable member in response to operation of the lock bolt or the transmission mechanism.