An auxiliary device module Z includes: an auxiliary device 1; a base board 2 mounted on the auxiliary device 1 which has terminals 5e; and a case 3 in which the base board 2 can be mounted. Fitting the base board 2 into the case 3, the terminals 5e of the base board 2 and electric wires 4 of a connecting portion 5e′ in the case 3 are connected electrically to form a connector 5. Positioning portions 6 for guiding the terminals 5e are provided in the connecting portion 5e′. Thereby, when assembling the auxiliary device module Z, connecting electrically the terminal 5e with the electric wires 4 can be done simultaneously, accurately and easily.