Provided is a GaN-based LED element having a novel structure for improving output by increasing light extraction efficiency. A GaN-based LED element comprising: a semiconductor laminated structure in which an n-type GaN-based semiconductor layer is arranged on the side of a lower surface of a p-type GaN-based semiconductor layer having an upper surface and the lower surface, and a light emitting part comprising a GaN-based semiconductor is interposed between the layers; a p-side electrode formed on the upper surface of the p-type GaN-based semiconductor layer; and an n-side electrode electrically connected to the n-type GaN-based semiconductor layer, wherein the p-side electrode comprises a transparent conductive film comprising a window region serving as a window for extracting light generated in the light emitting part, and a flat section and a rough surface section formed by a roughening treatment are arranged to form a predetermined mixed pattern on the upper surface of the p-type GaN-based semiconductor layer covered with the window region of the transparent conductive film.