In a light emitting device made of a group II-VI semiconductor of ZnCdSSe or MgZnCdSSe, to facilitate the movement of electrons or holes from a GaAs substrate to a group II-VI semiconductor film and to flow the current at a low voltage, a ZnSe--AlGaAs super lattice layer is formed between the group II-VI semiconductor film and the GaAs substrate so that the energy band from the substrate to the group II-VI semiconductor film rises in steps or gradually. In an device where an N-type semiconductor layer of the group II-VI semiconductor film is arranged on the side of the substrate, a P-type semiconductor film which raises the energy band from the electrode to the P-type semiconductor layer in steps is formed between the electrode and the P-type semiconductor layer which is the top layer of the group II-VI semiconductor film.