PURPOSE: To obtain a plastic container of high barrier character which gives high keeping quality to food or the like which is a content of the container by sheet molding a sheet which has two or more layers of thermoformable plastic film provided with an inorganic oxide film layer.

CONSTITUTION: A high barrier plastic container is formed by sheet molding of a sheet which has two or more layers of thermoformable plastic film provided with an inorganic oxide film layer by physical deposion. The film layer of inorganic oxide to be provided on the thermoformable plastic film layer is made of SixOy (x=1 or 2, y=0 to 3), MgO, Al2O3, SnO2 or the like, and the thickness of the film is preferable 500 to 2000. As the physical deposit, a vacuum deposit is most preferable in view of facility of manufacture and speed of film formation. If a barrier layer is provided as a middle layer, because of the existence of a plastic film with an inorganic oxide film layer on the outside, no influence of wet heat is given during retolt pasteurization and oxygen barrier charater can be retained.