Provided is a compact thin type optical unit provided also with a housing 2 having an mounting surface 31 for mounting an imaging device 18 on, an optical system driving device 5 for driving the optical system 3, a light quantity control member 16 for controlling a light quantity projecting on the imaging device 18 and a light quantity control driving device 6 for driving the light quantity control member 16, and the optical system driving device 5, wherein the light quantity control driving device 6 are arranged outside a same side of the mounting surface 31 so as to overlap each other in a direction perpendicular to an optical axis X of the optical system 3.