A coil bobbin to which an immobilizer coil is mounted, coil connecting terminals to which ends of the coil are connected, a fixed contact, a terminal for the fixed contact and connector terminals are integrally formed by resin molding into a coil bobbin integrated type insulator. Then, the coil connecting terminals, the terminal for the fixed contact, and the connector terminals are respectively soldered to a wiring board. All of them are incorporated in a body. In this manner, stress exerted on the soldered areas between the coil connecting terminals and the wiring board can be moderated to the substantially same extent as stress exerted on the soldered areas between the terminal for the fixed contact and the connector terminals, and the wiring board.