To simplify a manufacturing process, reduce its manufacturing cost, and prevent environmental disruption in disposal after use.

A paper blank-plate in which a bottom 1, side wall 2, and a flange 3 are integrated is made out of base paper, such as cup base-paper, and a paper container main body is made by placing the blank plate into a mold for vacuum or air-pressure forming, thereby forming it into a box. Further, a package container with a film 7 firmly joined to its entire inside is made by subjecting the heated thermoplastic resin inner protective film 7 to vacuum or air-pressure forming inside the paper container main body. Thereafter, stuff as contents 9 are filled into the package container, further, the package container is sealed under heat with a lid 11 attached to the flange 3 of the package container, and thus a package body is made.