Abstract: A container member is formed in a shape befitting accommodation and use of the substance to be contained therein, with a synthetic resin material capable of retaining its shape. This container member is provided along the open edge thereof with an extended edge adapted to be folded down outwardly. The container member is supported on a receptacle member having an upper edge possessed of a shape substantially similar to the outer shape of the open edge of the container member and disposed at the same height as the open edge, whereby the aforementioned extended edge, when folded down outwardly, firmly grips the upper edge of the receptacle member. After the container member is used, the folded portion of the extended edge is elongated to have the container member released from the receptacle member and thrown away.