An electromagnetic actuator including: an inner axial member; an outer housing member; a stator and a mover configured to have electromagnetic oscillation force exerted between them, each being securely assembled to different one of the members; and plate springs elastically connecting the members at opposite axial sides thereof, wherein the outer housing member includes an outer tubular member and first and second lid members attached to opposite axial openings thereof, and a first axial side of the outer tubular member has a small-diameter constricted section, and the constricted section has axially inner and outer stepped walls, and the axially inner stepped wall positions a first axial side of the stator or the mover assembled to the outer housing member, while the axially outer stepped wall and the first lid member support a periphery of the corresponding plate spring.