An electric power steering unit includes: a steering mechanism for steering a wheel under the torque of a steering wheel; a motor for adding a steering assist power to the steering mechanism; a controller for controlling current to be conducted through the motor in accordance with a steering state; a storage element for storing a state of the controller; and initial value setting device for causing the storage device to store a state of the controller when IG (ignition switch) is changed to OFF, and for obtaining a process of overheat state of the controller or the motor to set an initial value of a current limit value to the motor when the IG is changed to ON. As a result, not only a load on a battery when IG is OFF is reduced but also the motor is efficiently driven at the start time.