The laser semiconductor device includes a semiconductor substrate, a first clad layer of a first conductivity type, an active layer, a second clad layer of a second conductivity type, and a protective layer of the second conductivity type, and peak wavelength of photo luminescence of an active layer (window region) in a region near an end surface of a laser resonator is smaller than peak wavelength of photo luminescence of the active layer (active region) in an inner region of the laser resonator. In the active layer in the region near the end surface of the laser resonator, first impurity atoms of a second conductivity and second impurity atoms of the second conductivity exist mixedly, with the concentration of the first impurity atoms being higher than that of the second impurity atoms.