A multi-beam scanning apparatus has a multi-beam semiconductor laser which emits a plurality of laser beams, a laser holder holding the multi-beam semiconductor laser, a multi-beam light source unit having the multi-beam semiconductor laser and the laser holder, scanning imaging unit for scanning a plurality of laser beams emitted by the multi-beam semiconductor laser to form an image on a surface to be scanned, and a housing supporting the scanning imaging unit and the multi-beam light source unit. The multi-beam semiconductor laser is fixed to the laser holder with an inclination at or near a predetermined rotational angle for adjusting a beam interval between the plurality of laser beams.