Provided is a method for manufacturing a thermally-assisted magnetic recording head including a light source unit with a light source and a slider with an optical system. The method comprises steps of: adhering by suction the light source unit with a back holding jig; moving the back holding jig, then aligning a light-emission center of the light source with a light-receiving end surface of the optical system in directions within a slider back surface of the slider; bringing the light source unit into contact with the slider back surface, with a suction surface of the back holding jig tilted from the normal to the slider back surface; applying a load to a load application surface of the unit substrate by a loading means to bring a joining surface of the light source unit into conformity with the slider back surface; and bonding the light source unit and the slider. This method can improve the conformity, thereby achieving adequately strong junction and adequately high accuracy in position.