A motor control unit having an anti-burning device is provided which includes a rotation detection device for detecting whether the rotational speed of a given motor is below a predetermined level, a power supply limiting device for limiting the time of supplying current to the motor according to its rotational speed when the speed has been detected by the rotation speed detection device to be below the predetermined level. Thereby, the motor is prevented from burning, deteriorating in performance or shortening in life when the motor is overloaded. Also, the rotation detection device detects the condition when the motor is not rotating, and a cyclic power supply device for supplying current at a given cycle when the motor has been found to be not rotating by the aforementioned rotation detection device. Thereby, if the motor has been locked under an overload condition the motor can be readily restarted automatically when the load has been relieved.