An optical scanner includes a light source for projecting a light beam against a target, a deflector for deflecting the light beam, a coupling lens, an optical element, a light source support member, and a housing. The coupling lens directs the light beam to the deflector. The optical element focuses the light beam deflected by the deflector into a desired shape. The light source support member supports the light source. The housing houses the light source supported by the light source support member, the deflector, and the optical elements. The housing includes at least two coupling lens mounts on which the coupling lens is fixed on an optical path between the light source and the target, and accommodates multiple light source support members. The coupling lens is fixed to the coupling lens mount using an adhesive agent after an optical axis of the light beam is aligned.