PROBLEM TO BE SOLVED: To match an incident light direction and an exit light direction of an optical scanning unit while minimizing an increase in radial dimensions thereof.SOLUTION: An optical member 200 has a first fixed reflective surface 202, a second fixed reflective surface 204, a third fixed reflective surface 206, and a light transmissive surface 208. The first fixed reflective surface 202 is located on an opposite side from a second movable reflective section 104 in planar view with a first movable reflective section 102 in between. The second fixed reflective surface 204 is located between the first movable reflective section 102 and the second movable reflective section 104 in planar view. The third fixed reflective surface 206 is located on an opposite side from the first movable reflective section 102 in planar view with the second movable reflective section 104 in between. The light transmissive surface 208 is located between the first fixed reflective surface 202 and the third fixed reflective surface 206. The second fixed reflective surface 204 is located opposite the light transmissive surface 208 to reflect incident light entering the optical member 200 through the light transmissive surface 208.
