To stop a motor completely in a stop period when the motor is rotated at an extremely low speed by current control.

Driver elements Q1-Q4 supply a drive current to the motor, while a gate circuit 51 supplies gate signals to the driver elements Q1-Q4 so that a drive current value corresponds to a command value. Then, a current adjustment section supplies the command value in sequence to the gate circuit 51, sets the current values alternately to a first current value range in which the motor does not rotate and a second current value range in which the motor rotates, and, when the rotation amount of the motor reaches a predetermined value during the predetermined period, controls the gate circuit 51 to turn off the driver elements Q1-Q4 continuously until the end of the predetermined period.