In an optical device, an elastic support unit includes a pair of levers which face in a second direction perpendicular to a first direction, a pair of first torsion support portions which are connected between the levers and the base, a pair of second torsion support portions which are connected between the pair of levers and the movable unit, and a first link member that bridges the levers. The levers and the first link member define a light passage opening. Each of connection positions between the levers and the first torsion support portions is located on a side opposite to the movable unit with respect to the center of the light passage opening in a third direction perpendicular to the first direction and the second direction. A maximum width of the light passage opening in the second direction is defined by a gap between the levers in the second direction.