PURPOSE: To obtain a container capable of preserving contents semipermanently by sealing the container with simple constitution without increasing the size of the container itself, and preventing dew condensation from occurring in the container.

CONSTITUTION: A tapered side 3 is formed at the opening peripheral part of a bottomed container main body 2, and a cover having a tapered side 5 to be engaged with the tapered side 3 is formed. An air layer (A) is formed by forming a fixed gap between the outer peripheral plane of the bottomed container main body 2 covered with the cover 4 and covering it with a bottomed casing 7, and the dew condensation in a sealed container can be prevented from occurring by imparting an adiabatic effect to the bottomed container main body 2. A spring 9 is interposed between the bottom 6 of the casing 7 and the cover 4, and a connecting claw 11 formed at the lower terminal part of the casing 7 is connected to the bottom of the container main body 2. In this way, it is possible to press the cover onto the container main body 2 by the spring 9 and to hold the sealing capability of the container semipermanently via the tapered sides 3, 5.