A motor is provided with a rotation detector including a detection rotor and a detection stator placed to face the detection rotor. The motor further includes a motor case and a motor shaft protruding out of the motor case. The detection rotor is fixed to an end of the motor shaft. The detection rotor includes a plate and a coil provided on the plate. The plate is fixed to the end of the motor shaft. Specifically, the motor shaft includes an opening in the end. The plate has a circular disc shape and a cylindrical portion protruding in the center from the back side. The cylindrical portion is press-fitted in the opening of the motor shaft to fix the plate to the end of the motor shaft.