The present invention provides a semiconductor laser realizing reduced possibility that a wiring layer disposed in the air is broken even under severe environment of a large temperature difference. A trench is provided between adjacent ridges, and a wiring layer electrically connecting an upper electrode and a pad electrode is disposed in the air at least above the trench. The wiring layer in a portion above the trench has a flat shape or a concave shape which dents toward the trench. With the configuration, accumulation of strains in the wiring layer when the wiring layer repeats expansion and shrink under severe environment of a large temperature difference is suppressed.