To prevent an enlarging deformation of a shell of a container made of paper with longitudinal flutes due to an external force and an enlarging deformation of a shell of a container at a heating working time of a container content at a low cost by using a composite sheet obtained by adhesively laminating a synthetic resin softened by quenching after heating to soften having about a half value of a cost of a PET(polyester) film adhering sheet in a softened curtain state immediately after melting as a container material.

A method for manufacturing the container with flutes made of paper forms the container with the flutes by integrally standing molding the shell of the container having many vertical flutes on a periphery of a bottom of the container of paper. The method comprises the steps of heating the composite sheet obtained by adhesively laminating a synthetic resin layer 1 cured by quenching after heating to be softened by a press mold as heated pair of the adhesively laminated composite sheet 2, integrally standing forming the shell 5 of the container having the many vertical flutes 4 on the periphery of the bottom 3 of the container while softening the layer 1, quickly cooling the container 6 obtained by mold releasing, and curing the layer 1 to strengthening the rigidity of the flutes 4 to enable preventing of enlarging of the shell 5 of the container.