A nitride semiconductor laser chip is provided that offers sufficient reliability even at high output. The nitride semiconductor laser chip has a nitride semiconductor layer formed on a substrate, a resonator facet formed on the nitride semiconductor layer, and a coating film formed on the resonator facet and containing Ar. The coating film has, in a region contiguous with the resonator facet and in the vicinity thereof, a low-Ar region with a low Ar content and, on the side of this low-Ar region opposite from the resonator facet, a high-Ar region with a higher Ar content than the low-Ar region.