A fixing method for a resin lens in which a resin lens element is fixed to a resin lens frame, includes forming the resin lens element and the resin lens frame using amorphous polyolefin as a resin material therefor; forming an abutting surface in each of the resin lens element and the resin lens frame so as to mutually abut against each other; abutting the resin lens element and the resin lens frame mutually against each other at the abutting surfaces thereof; and laser welding the abutting surfaces to each other by irradiating a laser beam thereon.