A collapsible container which includes a rectangular bottom wall and sidewalls pivotally joined to respective outer edges of the bottom wall and is changeable between an assembled state in which the sidewalls are raised from the bottom wall and a folded state in which the sidewalls are folded to be superimposed on the bottom wall comprises a pair of band plate members extending along upper edges of a pair of first sidewalls opposed to each other and a band plate hinge mechanism joining the band plate members near to top surfaces of the first sidewalls so that the band plate members are pivotable between a horizontal posture of protruding from the first sidewalls horizontally inward and a rising posture of rising from the first sidewalls vertically upward. The band plate hinge mechanism is capable of positioning the band plate members in the horizontal posture. The band plate members assuming the horizontal posture are arranged as displaced lower relative to the top surfaces of the first sidewalls.