A method for fabricating a nitride semiconductor element according to the present invention comprises the steps of: forming a nitride semiconductor layer 13 on a base substrate 11; forming, on part of the upper surface of the nitride semiconductor layer 13, a conductive film 14 made of an electron emitting layer 14b and a dry etching mask layer 14a from bottom to top; performing dry etching on the nitride semiconductor layer 13; and performing wet etching on the nitride semiconductor layer 13 by emitting electrons from the nitride semiconductor layer 13 through the conductive film 14 to the outside.