A light emitting diode comprising: a conductive substrate; a first electrode layer disposed on the conductive substrate; a light emitting structure disposed on the first electrode layer, the light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer; a window layer disposed between the first electrode layer and the first semiconductor layer to reduce a reflectivity difference therebetween; and a second electrode layer electrically connected to the second semiconductor layer, wherein the first electrode layer comprises: a transparent electrode layer disposed between the conductive substrate and the first semiconductor layer; and an ohmic layer comprising a plurality of metal contact portions vertically passing through the transparent electrode layer, wherein each metal contact portion comprises AuBe, wherein at least one surface of the metal contact portion contacts the window layer, wherein a surface of the metal contact portion contacts the conductive substrate, characterised in that the window layer comprises a doping region doped with a dopant having the same polarity as the first semiconductor layer only in inner areas in which the window layer contacts the metal contact portion. a conductive substrate; a first electrode layer disposed on the conductive substrate; a light emitting structure disposed on the first electrode layer, the light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer; a window layer disposed between the first electrode layer and the first semiconductor layer to reduce a reflectivity difference therebetween; and a second electrode layer electrically connected to the second semiconductor layer, wherein the first electrode layer comprises: a transparent electrode layer disposed between the conductive substrate and the first semiconductor layer; and an ohmic layer comprising a plurality of metal contact portions vertically passing through the transparent electrode layer, wherein each metal contact portion comprises AuBe, wherein at least one surface of the metal contact portion contacts the window layer, wherein a surface of the metal contact portion contacts the conductive substrate, characterised in that the window layer comprises a doping region doped with a dopant having the same polarity as the first semiconductor layer only in inner areas in which the window layer contacts the metal contact portion. a transparent electrode layer disposed between the conductive substrate and the first semiconductor layer; and an ohmic layer comprising a plurality of metal contact portions vertically passing through the transparent electrode layer, wherein each metal contact portion comprises AuBe, wherein at least one surface of the metal contact portion contacts the window layer, wherein a surface of the metal contact portion contacts the conductive substrate, characterised in that the window layer comprises a doping region doped with a dopant having the same polarity as the first semiconductor layer only in inner areas in which the window layer contacts the metal contact portion.