An optical unit (10) includes: a plurality of lenses (L1 - L4) for imaging a subject image onto an imaging plane, which is a light receiving surface of a CCD (33) a diaphragm (BI) and an infrared absorption filter (F) arranged closer toward the imaging plane than the diaphragm (BI) and having a coating surface in which a YAG laser cutting film (FA) and an LD laser cutting film (FB) for cutting prescribed laser beams are film-formed. An F number (FNO), a maximum image height (IH), and a distance (Δd) between the imaging plane and a paraxial imaging position in a ghost light path in which the light emitted from the diaphragm (BI) is reflected at the imaging plane, then reflected by the coating surface, thereafter reaching the imaging plane again, satisfy the following formula (1):0.75
