PURPOSE: To reduce a space for a jacket of a container to a large extent as compared to a conventional type and to enhance heat exchange efficiency, by forming an expansion coupling structural part to the outer wall of the jacket.

CONSTITUTION: The upper jacket of a jacketted container 1 is fixedly mounted to the upper periphery of the container through a strip metal 3 and an expansion coupling structural part 5 is formed to the intermediate peripheral part thereof. Because the thermal change of the jacket 4 can be absorbed by said structural part 5 in this structure, the thickness of the strip metal 3, therefore, the space for the jacket S can be extremely reduced as compared to a conventional structure. On the other hand, the upper end of a bottom jacket 15 is welded to the side surface of the container 1 through the strip metal 3 while the lower leading end part thereof reaching the vicinity of the central part of the bottom surface of the container 1 in a curved form is connected to the bottom surface of the container in a state forming a coupling structural part 5' curved in a U-shape. This structural part 5' absorbs the thermal change of the jacket wall similarly to the aforementioned structural part 5.