In a semiconductor laser device, a first lead has a mounting portion for mounting a semiconductor laser element on its top surface via a submount member, and a lead portion extending from the mounting portion. Given that a direction in which a primary beam is emitted from the laser element is defined as a forward direction, and that a direction vertical to the forward direction and parallel to the top surface of the mounting portion is defined as a lateral direction, the first lead has, in one region of a side face of the mounting portion, a lateral reference surface which is parallel to a side face of the semiconductor laser element and flat. In the one region of the side face of the mounting portion, a recess portion is formed adjacent to the lateral reference surface.