Provided is a container that includes a portion in which a first film constituting a container body, a cut strip, a belt-shaped base, and a second film constituting the container body are superposed in the stated order. A joining region in which the first film, the cut strip, the belt-shaped base, and the second film are joined with each other is formed across the cut strip and the belt-shaped base, a tab is formed by a cut that penetrates through at least the first film and the cut strip in a non-joining region adjacent to the joining region, and the edge of the joining region on the tab side thereof is at least partially not orthogonal to the longitudinal direction of the cut strip.