To obtain a container which is excellent in heat resistance, cool resistance, impact resistance and water-tightness and is easy to open a lid by peripherally providing a seal which can be fitted/removed around each of peripheries of a container body and a lid made of a specific resin sheet and by making opening tabs including parts which do not overlap to protrude.

The container 1 comprises a container body 2 molded by a vacuum pressure-forming machine into a rectangle viewed from a plane wherein four corners exhibit an arc, and a lid 3. The container body 2 is equipped with a protruding rim 4 whose cross section exhibits an approximate hat shape around a peripheral site, while a protruding rim 5 whose cross section exhibits an approximate hat shape including a cavity to be fitted with the protruding rim 4 of the container body 2 is peripherally provided around a peripheral site of the lid 3, thereby forming a seal A which can be fitted/removed by the respective protruding rims 4, 5 of the container body 2 and the lid 3. Further, opening tabs 6, 7 having parts whose tips do not overlap each other are made to horizontally protrude from outer rims of the protruding rim 4 of the container body 2 and the protruding rim 5 of the lid 3 at the same corner site of the container body 2 and the lid 3.