A method for selectively growing a nitride semiconductor, in which a mask is formed, with an opening formed therein, on a nitride semiconductor layer. A nitride semiconductor crystal is selectively grown on a portion of the nitride semiconductor layer exposed through the opening in the mask, the nitride semiconductor crystal shaped as a hexagonal pyramid and having crystal planes inclined with respect to a top surface of the nitride semiconductor. Here, the nitride semiconductor crystal has at least one intermediate stress-relieving area having crystal planes inclined at a greater angle than those of upper and lower areas of the nitride semiconductor crystal, the intermediate stress-relieving area relieving stress which occurs from continuity in the inclined crystal planes.