A light emitting diode includes: a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer; a first contact electrode forming ohmic contact with the first conductive type semiconductor layer; a second contact electrode disposed on the second conductive type semiconductor layer; and an insulation layer disposed on the light emitting structure and insulating the first contact electrode from the second contact electrode, wherein the first conductive type semiconductor layer includes a nitride-based substrate, the nitride-based substrate having a thread dislocation density of 104 cm−2 or less, an oxygen impurity concentration of 1019 cm−3 or less, and an optical extinction coefficient of less than 5 cm−1 at a wavelength of 465 nm to 700 nm.