A light emitting diode includes a first conductivity type semiconductor layer and a mesa disposed on the first conductivity type semiconductor layer wherein the mesa is a semiconductor stack including an active layer and a second conductivity type semiconductor layer; a ZnO layer disposed on the second conductivity type semiconductor layer; a lower insulation layer covering the ZnO layer and the mesa, and including an opening exposing the ZnO layer; a first pad metal layer disposed on the lower insulation layer, and electrically connected to the first conductivity type semiconductor layer; a second pad metal layer electrically connected to the ZnO layer through the opening of the lower insulation layer, and an upper insulation layer covering the first pad metal layer and the second pad metal layer.