A semiconductor laser device includes a semiconductor-layer lamination (20) having an active layer (26) formed over a substrate (11). The semiconductor-layer lamination (20) includes a front face which emits light, a strip-shaped optical waveguide formed in a direction transverse to the front face, a first region (20A) extending in a direction transverse to the front face, a second region (20B) having a top surface whose height is different from that of the first region (20A), and a planar region (20C) formed between the first region (20A) and the second region (20B), and having periodic surface undulations whose variation is smaller than that of the second region (20B). The optical waveguide is formed in the planar region (20C).