A nitride semiconductor laser device includes: a substrate made of silicon in which a plane orientation of a principal surface is a {100} plane; and a semiconductor laminate that includes a plurality of semiconductor layers formed on the substrate and includes a multiple quantum well active layer, each of the plurality of semiconductor layers being made of group III-V nitride. The semiconductor laminate has a plane parallel to a {011} plane which is a plane orientation of silicon as a cleavage face and the cleavage face constructs a facet mirror.