The present disclosure provides a resolver including a stator core, an insulation cover for covering and insulating the stator core, an upper protection cover coupled to an upper portion of the insulation cover to cover and protect upper portions of coils wound around the stator core, a lower protection cover coupled to a lower portion of the insulation cover to cover and protect lower portions of the coils, a hook configured to extend from the upper protection cover in the downward direction, and a hook-catching portion formed at the insulation cover such that the lower end portion of the hook is hooked thereon in the upward direction.