A light emitting device includes a support member, a light emitting structure on the support member, the light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the second conductive type semiconductor layer and the first conductive type semiconductor layer, a first nitride semiconductor layer disposed on the second conductive type semiconductor layer, a second nitride semiconductor layer disposed on the first nitride semiconductor layer and including an uneven structure, and a first electrode pad disposed on the light emitting structure wherein the second nitride semiconductor layer has an opening, the first electrode pad is in contact with the first nitride semiconductor layer through the opening, and the first nitride semiconductor layer has a work function smaller than that of the second nitride semiconductor layer.