A multilayer sheet harmless to human beings, having a certain gas-barrier property, and comprising an easily-produced metal film layer and a packaging material made of the multilayer sheet. The multilayer sheet is composed of at least a resin film layer and a metal film layer of magnesium or a magnesium alloy integrally formed on the resin film layer by evaporation, electron beam, or sputtering. Magnesium is harmless to human beings, and therefore such a multilayer sheet can be preferably used as a material of a food or medicine bag.