A light emitting diode, comprising: a first conductivity type semiconductor layer; a mesa comprising a second conductivity type semiconductor layer disposed on the first conductivity type semiconductor layer and an active layer interposed between the second conductivity type semiconductor layer and the first conductivity type semiconductor layer; a first contact layer comprising an outer contact portion (335a2) contacting the first conductivity type semiconductor layer near an edge of the first conductivity type semiconductor layer along a periphery of the mesa and an inner contact portion (335a1) contacting the first conductivity type semiconductor layer in a region surrounded by the outer contact portion; a second contact layer disposed on the mesa and contacting the second conductivity type semiconductor layer; a first insulation layer (329, 333) covering the first conductivity type semiconductor layer and the mesa, and insulating the first contact layer from the mesa and the second contact layer, wherein the first insulation layer (329, 333) exposes the first conductivity type semiconductor layer for the outer contact portion (335a2) and the inner contact portion (335a1) to contact the first conductivity type semiconductor layer, and wherein the outer contact portion (335a2) and the first insulation layer (329, 333) alternately contact the first conductivity type semiconductor layer along a side surface of the mesa, characterized in that the first insulation layer (329, 333) comprises a protrusion and a recess around the mesa, wherein the first contact layer contacts the first conductivity type semiconductor layer at the recess of the first insulation layer (329, 333), or the first contact layer comprises a protrusion and a recess around the mesa, wherein the protrusion of the first contact layer contacts the first conductivity type semiconductor layer, and the recess is disposed on the first insulation layer (329, 333). a first conductivity type semiconductor layer; a mesa comprising a second conductivity type semiconductor layer disposed on the first conductivity type semiconductor layer and an active layer interposed between the second conductivity type semiconductor layer and the first conductivity type semiconductor layer; a first contact layer comprising an outer contact portion (335a2) contacting the first conductivity type semiconductor layer near an edge of the first conductivity type semiconductor layer along a periphery of the mesa and an inner contact portion (335a1) contacting the first conductivity type semiconductor layer in a region surrounded by the outer contact portion; a second contact layer disposed on the mesa and contacting the second conductivity type semiconductor layer; a first insulation layer (329, 333) covering the first conductivity type semiconductor layer and the mesa, and insulating the first contact layer from the mesa and the second contact layer, wherein the first insulation layer (329, 333) exposes the first conductivity type semiconductor layer for the outer contact portion (335a2) and the inner contact portion (335a1) to contact the first conductivity type semiconductor layer, and wherein the outer contact portion (335a2) and the first insulation layer (329, 333) alternately contact the first conductivity type semiconductor layer along a side surface of the mesa, characterized in that the first insulation layer (329, 333) comprises a protrusion and a recess around the mesa, wherein the first contact layer contacts the first conductivity type semiconductor layer at the recess of the first insulation layer (329, 333), or the first contact layer comprises a protrusion and a recess around the mesa, wherein the protrusion of the first contact layer contacts the first conductivity type semiconductor layer, and the recess is disposed on the first insulation layer (329, 333).