In a motor, a magnetic sensor is provided on the lower surface of a substrate disposed above a magnetic sensor. On an upper surface of the substrate, a plate-shaped magnetic member is disposed at a position axially overlapping the magnetic sensor. The substrate and the magnetic member are fixed to each other at a plurality of fixing positions by axial tightening. On the upper surface of the magnetic member, a rib extending to connect the vicinity of one fixing position and the vicinity of another fixing position is provided. Flexure of the magnetic member is significantly reduced and prevented by this rib. For this reason, the direction of the magnetic flux of a magnet is concentrated on the magnetic sensor side. As a result, detection accuracy of the magnetic sensor is significantly improved.