A light emitting diode comprising: a light emitting structure formed on a substrate and comprising a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer; mesa-etched areas formed from the surface of the second conductivity type semiconductor layer to the first conductivity type semiconductor layer; a reflective electrode formed on the second conductivity type semiconductor layer and including a reflective metal layer, a barrier metal layer and a stress relieving layer formed between the reflective metal layer and the barrier metal layer, wherein the stress relieving layer has a coefficient of thermal expansion between the coefficient of thermal expansion of the reflective metal layer and the coefficient of thermal expansion of the barrier metal layer; a lower insulation layer covering an overall surface of the structure formed by the first conductivity type semiconductor layer, the active layer, the second conductivity type semiconductor layer, the mesa-etched areas and the reflective electrode, with the lower insulation layer allowing an upper surface of the reflective electrode to be partially exposed therethrough and further having openings disposed near an edge of the substrate which allow the surface of the first conductivity type semiconductor layer to be exposed therethrough in the mesa-etched areas; a current spreading layer formed on the lower insulation layer covering the first conductivity type semiconductor layer and being electrically connected to the first conductivity type semiconductor layer; an upper insulation layer formed on the current spreading layer, with both the current spreading layer and the reflective electrode being partially exposed through the upper insulation layer; a first pad electrically connected to the current spreading layer exposed through the upper insulation layer; and a second pad electrically connected to the reflective electrode exposed through the upper insulation layer. a light emitting structure formed on a substrate and comprising a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer; mesa-etched areas formed from the surface of the second conductivity type semiconductor layer to the first conductivity type semiconductor layer; a reflective electrode formed on the second conductivity type semiconductor layer and including a reflective metal layer, a barrier metal layer and a stress relieving layer formed between the reflective metal layer and the barrier metal layer, wherein the stress relieving layer has a coefficient of thermal expansion between the coefficient of thermal expansion of the reflective metal layer and the coefficient of thermal expansion of the barrier metal layer; a lower insulation layer covering an overall surface of the structure formed by the first conductivity type semiconductor layer, the active layer, the second conductivity type semiconductor layer, the mesa-etched areas and the reflective electrode, with the lower insulation layer allowing an upper surface of the reflective electrode to be partially exposed therethrough and further having openings disposed near an edge of the substrate which allow the surface of the first conductivity type semiconductor layer to be exposed therethrough in the mesa-etched areas; a current spreading layer formed on the lower insulation layer covering the first conductivity type semiconductor layer and being electrically connected to the first conductivity type semiconductor layer; an upper insulation layer formed on the current spreading layer, with both the current spreading layer and the reflective electrode being partially exposed through the upper insulation layer; a first pad electrically connected to the current spreading layer exposed through the upper insulation layer; and a second pad electrically connected to the reflective electrode exposed through the upper insulation layer.