To prevent the breakage of a housing by improving the corrosion resistance of a reinforcing member.

In a control switch, an elliptic bolt insertion hole 31 into which a bolt for fitting the housing 1 to a vehicle body (or an automatic transmission) is inserted, and a cylindrical reinforcing member 30 passing therethrough are formed in a flange 6 of a housing 1 (a body 1a) by insert molding. A reinforcing member 6 is formed of aluminum or an aluminum alloy coated with a positive electrode oxide film at the surface thereof. Since the surface of the reinforcing member 30 is coated with the positive electrode oxide film, even if a corrosive material such as a snow melting agent is adhered to the reinforcing member 30, the corrosion of the reinforcing member 30 is prevented to prevent the breakage of a part (the flange 6) covering the reinforcing member 30 of the housing 1. Furthermore, limitation in fitting position of the housing 1 caused by the avoidance of the corrosion of the reinforcing member 30 can be avoided.