To provide an optical scanner in which the effect on the optical characteristics can be suppressed when an optical element is deformed.

A light source 3 emitting a light beam, a deflector 4 for deflecting/scanning a luminous flux from the light source 3, and optical elements 6, 8 for focusing the luminous flux reflected on the deflector 4 on the surface of a photosensitive body are housed in an optical housing 1 with the reflective optical element 6 being urged with an appropriate pressure using a leaf spring 5. According to the structure, the reflective optical element 6 is held in the optical housing 1 while allowing deformation thereof.