The present invention aims at providing a phosphor thin film capable of realizing a light-emitting device attaining an excellent response, favorable color purity, and emission with a high luminance; and an EL panel including the same. The EL panel including the phosphor thin film of the present invention comprises a substrate, and a lower electrode, an insulating layer, an EL phosphor laminate thin film, and an upper electrode which are successively laminated on the substrate. In the EL phosphor laminate thin film, buffer thin films are formed on both sides of a phosphor thin film comprising a matrix material which is essentially constituted by magnesium gallate and doped with a rare-earth element or the like, and electron injection thin films are further formed on both sides thereof.