An electric motor which is an in-wheel motor includes a motor housing, a motor stator, a rotation shaft, a motor rotor, and a rotational sensor. The rotation shaft has: a shaft portion rotatably supported by a plurality of bearings; a flange portion spreading toward the outer diameter side from the outer circumference of the shaft portion; and a cylindrical portion extending from the outer diameter end of the flange portion in parallel with the shaft portion, and having an outer circumference to which the motor rotor is fitted. The axial position of the rotational sensor is between the plurality of bearings, and the rotational sensor is provided on the inner diameter side of the cylindrical portion of the rotation shaft.