A light emitting device comprising: a conductive substrate forming a second electrode layer; a plurality of light emitting cells (P1 to P4) disposed on the second electrode layer, wherein each of the plurality of light emitting cells includes a first conduction type semiconductor layer in contact with the second electrode layer, a second conduction type semiconductor layer, and an active layer between the first conduction type semiconductor layer and the second conduction type semiconductor layer; a protective layer (135-1 to 135-3) disposed to cover a side of the first conduction type semiconductor layer and a side of the active layer, a part of the protective layer being disposed on the second electrode layer in boundary regions between the light emitting cells; first electrodes (210 to 240; 310) disposed on the second conduction type semiconductor layers of the plurality of light emitting cells, respectively; and connection electrodes (172 to 178; 320) disposed at sides of the light emitting cells (P1 to P4) and on the second electrode layer in the boundary regions to connect the first electrodes to each other, wherein the first electrodes include third electrodes (212, 222, 232, 242; 312) disposed on edge regions of an upper side of a respective one of the light emitting cells (P1 to P4), wherein the third electrodes (212, 222, 232, 242; 312) are extended to a side of the second conduction type semiconductor layer and contact the side of the second conduction type semiconductor layer, wherein the connection electrodes (172 to 178; 320) connect the third electrodes (212, 222, 232, 242; 312) to each other, wherein said part of the protective layer is disposed between the connection electrodes (172 to 178) and the second electrode layer in the boundary region, wherein the protective layer further includes protruding portions extending to an inside of each of the light emitting cells (P1 to P4) from the side of the first conduction type semiconductor layer and the side of the active layer. a conductive substrate forming a second electrode layer; a plurality of light emitting cells (P1 to P4) disposed on the second electrode layer, wherein each of the plurality of light emitting cells includes a first conduction type semiconductor layer in contact with the second electrode layer, a second conduction type semiconductor layer, and an active layer between the first conduction type semiconductor layer and the second conduction type semiconductor layer; a protective layer (135-1 to 135-3) disposed to cover a side of the first conduction type semiconductor layer and a side of the active layer, a part of the protective layer being disposed on the second electrode layer in boundary regions between the light emitting cells; first electrodes (210 to 240; 310) disposed on the second conduction type semiconductor layers of the plurality of light emitting cells, respectively; and connection electrodes (172 to 178; 320) disposed at sides of the light emitting cells (P1 to P4) and on the second electrode layer in the boundary regions to connect the first electrodes to each other, wherein the first electrodes include third electrodes (212, 222, 232, 242; 312) disposed on edge regions of an upper side of a respective one of the light emitting cells (P1 to P4), wherein the third electrodes (212, 222, 232, 242; 312) are extended to a side of the second conduction type semiconductor layer and contact the side of the second conduction type semiconductor layer, wherein the connection electrodes (172 to 178; 320) connect the third electrodes (212, 222, 232, 242; 312) to each other, wherein said part of the protective layer is disposed between the connection electrodes (172 to 178) and the second electrode layer in the boundary region, wherein the protective layer further includes protruding portions extending to an inside of each of the light emitting cells (P1 to P4) from the side of the first conduction type semiconductor layer and the side of the active layer.