Disclosed are a light emitting device, a light emitting device package, and a lighting system. The light emitting device includes an electrode layer, a current density adjusting pattern on the electrode layer, and a light emitting structure on the electrode layer and the current density adjusting pattern. The light emitting structure includes a second conductive semiconductor layer, an active layer on the second conductive semiconductor layer, and a first conductive semiconductor layer on the active layer. The first conductive semiconductor layer includes an upper portion including a column pattern or a hole pattern serving as a structure of a resonant cavity and a lower portion having a thickness less than a thickness of the upper portion.