The magnetic refrigerant for the Ericsson type magnetic refrigerator should have a constant magnetic entropy difference DELTA S//J between two constant magnetic field processes. However, the magnetic entropy change of an homogeneous ferromagnet exhibits a sharp peak at the Curie temperature. In the present investigation we have succeeded to make the layer structural sintered composite composed of several kinds of RAl//2 compounds having large entropy change near their Curie temperatures and made clear that this composite has the constant DELTA S//J in the wide temperature range suitable for the Ericsson cycle.