A linear motor provided with a stator extending in a predetermined direction and a movable piece being movable along the stator, comprises:a field magnet arranged at the stator;an armature coil arranged at the movable piece and opposed to the field magnet; anda drive circuit for energizing the armature coil and thereby driving the movable piece, the drive circuit being formed at an electric circuit-board arranged on the movable piece.An image reader for optically scanning and reading an original image, comprises:a slider carrying an illumination light source for emitting light to the original image and being driven linearly in a predetermined direction;a stator provided with a field magnet having N- and S-type magnetic poles arranged alternately and linearly in the predetermined direction;a movable piece having an armature coil opposed to the field magnet, being movable along the stator, and coupled to the slider; anda drive circuit for energizing the armature coil and thereby driving the movable piece, the drive circuit being formed at an electric circuit-board arranged on the movable piece.