A marking (7) that indicates inherent information about a stator (2), is formed of recesses inscribed at a predetermined position on the outer circumferential surface of a laminated iron core (21) of the stator (2), by melting a magnetic thin plate with a laser beam. The marking (7) is formed of recesses in the outer circumferential surface of the laminated iron core (21), i.e., in the outer circumferential surface, at the laminated side of the magnetic thin plate, of the laminated iron core (21). Accordingly, friction or the like does not peel off the marking.