An electric power steering device includes: an information obtaining unit that obtains information on a steering torque acting on a steering wheel of a vehicle, speed of the vehicle, a turn angle of the steering wheel, and an actual yaw rate; a setting unit that sets a steering assist control amount relating to an assist motor based a deviation of the actual yaw rate from a norm yaw rate set based on a traveling state of the vehicle; and a steering assist control unit that performs steering assist control using the assist motor based on the information on the steering torque. The steering assist control unit performs the steering assist control based on the steering assist control amount set by the setting unit.