To provide an electric power steering device capable of ensuring a required amount of current even when a switch provided between a motor and a battery side is miniaturized.

The switch 8 manufactured using fine electric mechanical system technology is provided between the motor for assisting steering and an on-vehicle battery side. An energization passage for connecting the motor and the on-vehicle battery side is electrically connected in parallel by contacting a plurality of conductors 88 (movable contact part) possessed by the switch 8 with conductor passages 82, 83 (fixed contact part). Further, feeding/shutting off of electric power from the battery to the motor is switched by contacting/non-contacting the conductor 88, the movable contact parts with the conductor passages 82, 83, i.e., the fixed contact part.