Provided are a vertical nitride semiconductor device in which occurrence of leak currents can be suppressed, and a method for manufacturing such nitride semiconductor device. A nitride semiconductor device, which is a vertical HEMT, is provided with an n− type GaN first nitride semiconductor layer, p+ type GaN second nitride semiconductor layers, an n− type GaN third nitride semiconductor layer, and an n− type AlGaN fourth nitride semiconductor layer that is in hetero junction with a front surface of the third nitride semiconductor layer. Openings that penetrate the third nitride semiconductor layer and reach front surfaces of the second nitride semiconductor layers are provided at positions isolated from the peripheral edge of the third nitride semiconductor layer. Source electrodes are provided in the openings. Etching damage that is in contact with the source electrodes is surrounded by a region where no etching damage is formed.