An actuator has: an affixed section having a coil; a first mobile section that is elastically held and disposed so as to allow movement in the axial direction inside one end of the coil, and has a first magnet magnetized in the axial direction of the coil and disposed on one end in the axial direction; and a second mobile section that is elastically held and disposed so as to allow movement in the axial direction inside another end of the coil, and has a second magnet magnetized in the axial direction and disposed on the other end in the axial direction. The first and second magnets are disposed such that identical magnetic poles are in the same direction in the axial direction, and the first and second mobile sections move in opposite directions along the same axis when a current is applied to the coil.