Abstract: Provided is an electric power steering device including: a motor; a drive device that supplies the motor with three-phase alternating current electric power; and a control device that controls the drive device, in which the control device is connected to a first power supply path that supplies power to the control device not via an ignition switch and a second power supply path that supplies power to the control device via the ignition switch, and the control device, in a case of detecting a failing of the first power supply path, operates with power supplied from the second power supply path and makes the motor generate an electromagnetic brake.