A motor speed control circuit includes: a first determining circuit configured to determine whether a rotation speed of a motor is higher than a set first rotation speed based on a speed signal corresponding to the rotation speed; a second determining circuit configured to determine whether the rotation speed is higher than a set second rotation speed, which is higher than the first rotation speed, based on the speed signal; and a drive signal output circuit configured to output to a drive circuit configured to drive the motor a drive signal for increasing the rotation speed when the rotation speed is lower than the first rotation speed and decreasing the rotation speed when the rotation speed is higher than the second rotation speed, based on determination results of the first and second determining circuits.