A motor control unit having a motor structure that rotates a rotor by voltage excitation includes a photo interrupter, a slit rotation plate, a comparator, and an encoder circuit in order to obtain a position detection signal corresponding to a rotational phase of an output shaft. During a period of time from the motor stopping to the change of the output of an encoder circuit after the supply of a drive voltage waveform, a CPU supplies a drive voltage waveform that is advanced by an advance angle amount that has been set in advance to the motor, and after the change of the output of the encoder circuit, a drive signal by which the advance angle amount is controlled based on the output of the encoder circuit is supplied to the motor.