Disclosed herein is a UV light emitting diode. The UV light emitting diode includes a first conductive type semiconductor layer; a first stress adjustment layer disposed on the first conductive type semiconductor layer, and including a first nitride layer including Al and a second nitride layer disposed on the first nitride layer and having a lower Al composition ratio than the first nitride layer; an active layer disposed on the first stress adjustment layer; and a second conductive type semiconductor layer disposed on the active layer, wherein the first stress adjustment layer includes an Al delta layer inserted in the first nitride layer, and a lower surface of the first nitride layer in which the Al delta layer is inserted has greater average tensile stress than a lower surface of the second nitride layer directly disposed on the first nitride layer.