A polar electromagnet device has a drive shaft comprising an axis center supported so as to reciprocate in an axis center direction at a center hole of a spool wound with a coil, and a movable iron core attached to a lower end of the drive shaft on the axis center. The drive shaft is reciprocated with the movable iron core which reciprocates based on excitation and demagnetization of the coil. A permanent magnet is integrally arranged at the movable iron core on the same axis center.