PURPOSE: To obtain a container having a sufficient heat resistance by a method wherein the body and bottom parts of a container are made up of the container- like blank thermoformed of a predetermined plastic sheet and of the polyethylene terephthalate injection molded on the blank surface and the flange part of the container is injection molded from polyethylene terephthalate.

CONSTITUTION: Since a flange part 15 of a container 14 is injection molded from a dimensionally stable polyethylene terephthalate, the flange part 15 can be formed into a predetermined thickness and width with a high degree of accuracy and a predetermined strength of the flange part can be obtained. For this reason, an accurate double seam can be made of the peripheral edge part 12 of a metal lid 11. Also, since the body part 16a and the bottom part 16b of the container 14 are formed of a container-like blank 21 consisting of the plastic sheet having a predetermined heat resistance and transparency and a transparent polyethylene terephthalate 25 injection molded on the surface of the container-like blank 21, the container 14 excellent in heat resistance and transparency can be obtained.