An actuator includes an arm starting end having a piezoelectric element, a first end of the arm starting end connected to an inner side of a fixed frame, the arm starting end extending in a straight line, along a Y-axis direction through a gap between the fixed frame and a mirror surface, from the first end to beyond a middle point of an outer side of the mirror surface; an arm terminating end including a first end connected to the middle point of the outer side of the mirror surface, the arm terminating end extending parallel to the arm starting end; and an arm relay that connects a second end of the arm starting end to a second end of the arm terminating end, the arm relay being formed in a zigzag.