To improve the positioning accuracy of a driven member driven by a motor, having a reduction gear mechanism.

A hole IC 37 for absolute position detection which detects a reference position of an output shaft 34 is formed on the surface of a printed circuit board 36 so as to face a magnet 41 fitted on the outer periphery of the side of a drive gear 35, when the output shaft 34 is at a reference position. Holes IC 38, 39 for relative position detection which detects the rotational angle of a rotating shaft 15 are formed on the surface of the printed circuit board 36, so as to face a multi-pole polarizing magnetic 42 fitted on the front end 15a of the rotating shaft 15.