Disclosed are a light emitting device. A light emitting diode comprises a light emitting device comprises a plurality of N-type semiconductor layers including a first N-type semiconductor layer and a second N-type semiconductor layer on the first N-type semiconductor layer, an active layer on the second N-type semiconductor layer, and a P-type semiconductor layer on the active layer, wherein the first N-type semiconductor layer comprises a Si doped Nitride layer and the second N-type semiconductor layer comprises a Si doped Nitride layer, and wherein the first and second N-type semiconductor layers have a Si impurity concentration different from each other.