A light emitting device comprising: a light emitting structure comprising a first semiconductor layer, a second semiconductor layer, and an active layer between the first and second semiconductor layers; a first electrode electrically connected to the first semiconductor layer; and a second electrode disposed over the second semiconductor layer, wherein the second electrode comprises: a reflective electrode layer disposed over the second semiconductor layer; and a bonding electrode layer disposed in at least a partial region of an outer side surface of the reflective electrode layer while coming into contact with the second semiconductor layer, wherein the bonding electrode layer has a structure in which a chromium (Cr) layer, an aluminum (Al) layer, a nickel (Ni) layer, and a gold (Au) layer are laminated in this order, wherein the chromium layer is disposed to come into contact with the upper surface of the second semiconductor layer, wherein said reflective electrode layer of said second electrode comprises a structure in which at least a first aluminum (Al) layer, a first nickel (Ni) layer, and a first gold (Au) layer are laminated in this order, and wherein first Al layer is disposed to come into contact with an upper surface of said second semiconductor layer. a light emitting structure comprising a first semiconductor layer, a second semiconductor layer, and an active layer between the first and second semiconductor layers; a first electrode electrically connected to the first semiconductor layer; and a second electrode disposed over the second semiconductor layer, wherein the second electrode comprises: a reflective electrode layer disposed over the second semiconductor layer; and a bonding electrode layer disposed in at least a partial region of an outer side surface of the reflective electrode layer while coming into contact with the second semiconductor layer, wherein the bonding electrode layer has a structure in which a chromium (Cr) layer, an aluminum (Al) layer, a nickel (Ni) layer, and a gold (Au) layer are laminated in this order, wherein the chromium layer is disposed to come into contact with the upper surface of the second semiconductor layer, wherein said reflective electrode layer of said second electrode comprises a structure in which at least a first aluminum (Al) layer, a first nickel (Ni) layer, and a first gold (Au) layer are laminated in this order, and wherein first Al layer is disposed to come into contact with an upper surface of said second semiconductor layer. a reflective electrode layer disposed over the second semiconductor layer; and a bonding electrode layer disposed in at least a partial region of an outer side surface of the reflective electrode layer while coming into contact with the second semiconductor layer, wherein the bonding electrode layer has a structure in which a chromium (Cr) layer, an aluminum (Al) layer, a nickel (Ni) layer, and a gold (Au) layer are laminated in this order, wherein the chromium layer is disposed to come into contact with the upper surface of the second semiconductor layer, wherein said reflective electrode layer of said second electrode comprises a structure in which at least a first aluminum (Al) layer, a first nickel (Ni) layer, and a first gold (Au) layer are laminated in this order, and wherein first Al layer is disposed to come into contact with an upper surface of said second semiconductor layer.