A light emitting device comprising: a conductive substrate; a reflective layer on the conductive substrate; an etching protective layer on a peripheral portion of a top surface of the conductive substrate; and a light emitting structure, which is formed on the reflective layer and the etching protective layer such that the etching protective layer is partially exposed and the light emitting structure includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer and an active layer between the first and second conductivity type semiconductor layers, a bonding layer disposed between the reflective layer and the conductive substrate to bond the conductive substrate with the reflective layer, an electrode on the light emitting structure, wherein the electrode is disposed on the top surface of the first conductivity type semiconductor layer, wherein the etching protective layer includes a first refractive layer having a first refractive index and a second refractive layer having a second refractive index greater than the first refractive index, wherein the etching protective layer is disposed on the peripheral portion of the top surface of the bonding layer, characterized in that a nitride semiconductor layer having a light extraction structure is disposed on the first conductivity type semiconductor layer of the light emitting structure, the nitride semiconductor layer has an open space exposing a top surface of the first conductivity type semiconductor layer, and the electrode is disposed on the exposed top surface of the first conductivity type semiconductor layer. a conductive substrate; a reflective layer on the conductive substrate; an etching protective layer on a peripheral portion of a top surface of the conductive substrate; and a light emitting structure, which is formed on the reflective layer and the etching protective layer such that the etching protective layer is partially exposed and the light emitting structure includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer and an active layer between the first and second conductivity type semiconductor layers, a bonding layer disposed between the reflective layer and the conductive substrate to bond the conductive substrate with the reflective layer, an electrode on the light emitting structure, wherein the electrode is disposed on the top surface of the first conductivity type semiconductor layer, wherein the etching protective layer includes a first refractive layer having a first refractive index and a second refractive layer having a second refractive index greater than the first refractive index, wherein the etching protective layer is disposed on the peripheral portion of the top surface of the bonding layer, characterized in that a nitride semiconductor layer having a light extraction structure is disposed on the first conductivity type semiconductor layer of the light emitting structure, the nitride semiconductor layer has an open space exposing a top surface of the first conductivity type semiconductor layer, and the electrode is disposed on the exposed top surface of the first conductivity type semiconductor layer.