Abstract: A container can be easily manufactured because the container can be manufactured by die-forming a resin sheet. The container widens toward an outer circumferential side from side parts differing from a long side part on which a hinge part is formed, and is furnished with joining parts having mating surfaces that join with one another, and bent parts at outer circumferential edges of the joining parts, the bent parts being bent between container body parts in a direction in which the two separate from one another. Consequently, the container can maintain a freestanding form on an installation surface using the bent parts which spread so as to mutually separate, as legs. The above facilitates production and makes it possible for the container to stand in a stable state.