A nitride semiconductor device according to the present invention sequentially includes at least an n-electrode, an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The n-type semiconductor layer includes: an n-type GaN contact layer including n-type impurity-doped GaN having an electron concentration ranging from 5×1016 cm−3 to 5×1018 cm−3; the n-electrode provided on one of a main surface of the n-type GaN contact layer; and a generating layer provided on other main surface of the n-type GaN contact layer, including at least any one of AlxGa1-xN (0