A light emitting diode includes an epitaxial substrate, an active layer, a tunneling layer, a current spreading layer, and an electrode unit. The active layer includes a first conductive type film, a quantum well structure, and a second conductive type film that is made from AlyInzGa(1-y-z)N, wherein 0 y. The tunneling layer has a band gap greater than that of the second conductive film. The current spreading layer is stacked on the tunneling layer.