<p>The steering lock includes a cover (70) on which a support structure (71,81) for supporting a lock mechanism (30) is integrally formed. The lock mechanism is attached to the cover to assemble a first subunit. A steering lock ECU (113) is attached to an ECU case (110) to assemble a second subunit. The first subunit is attached to the second subunit to assemble a lock unit (20). The lock unit is attached to the housing (10). A bolt (6) fastens the lock unit and the housing to each other.</p>