Disclosed are a light emitting device, a method of manufacturing the same, a light emitting device package, and a lighting system. The light emitting device includes: a substrate; a first conductive semiconductor layer on the substrate; an active layer on the first conductive semiconductor layer; a second conductive semiconductor layer; and a nitride semiconductor layer having a refractive index less than a refractive index of the second conductive semiconductor layer on the second conductive semiconductor layer. The light emitting device, the method of manufacturing the same, the light emitting device package and the lighting system has the advantage that light extraction efficiency is improved.