PURPOSE: To give a container a property to keep the odor of the contents and enable it to preserve even a highly permeative liquid in a stabilized state by laying tubular bodies one upon another, in forming the container, in a manner that that part of a tubular body which consists of saturated polyester is placed in contact with the inner layer of an end of another tubular body and that part which consists of a polyolefin resin, in contact with the outer layer of the end, followed by their adhesion by thermal fusion.

CONSTITUTION: That part 33a at the left end of a body panel 11 of blank board which consists of a polyolefin resin is fused under heat to the outer layer 33 of a panel for thermal fusion 15, whereas that part 34a of the panel for thermal fusion 15 of blank board which consists of saturated polyester is fused under heat to the inner layer 34 of the body panel 11. Since the thermal fusion of the tubular bodies is effected between parts of the same polyolefin resin and between parts of the same saturated polyester, the thermal fusion results in an extremely high strength and achievement of an excellent strength in a container.