A light emitting diode including a GaN substrate, a first type semiconductor layer, a light emitting layer, a second type semiconductor layer, a first electrode, and a second electrode is provided. The GaN substrate has a first surface and a second surface opposite thereto, and the second surface has a plurality of protuberances, the height of the protuberance is h μm and the distribution density of the protuberance on the second surface is d cm−2, wherein 9.87×107≦h2d, and h≦1.8. The first type semiconductor is disposed on the first surface of the GaN substrate. The light emitting layer is disposed on a partial region of the first semiconductor layer, and the wavelength of the light emitted by the light emitting layer is from 375 nm to 415 nm. The second semiconductor layer is disposed on the light emitting layer.