To provide an overhang door lower parts swing stopper capable of stably guiding the movement of an overhang door by securely holding guide pieces.

This overhang door is constituted of a floor surface installation member 3 having a base 1 installed on a floor surface F and a pair of guide pieces 2 housed in the base 1 and free to swingably protrude diagonally upward, and a guide groove member 4 arranged in an overhang door body D into which the swingably protruded guide pieces 2 of the floor surface installation member 3. The pair of guide pieces 2 are arranged in parallel with and opposite to each other so that they may cross each other at a position where they swingably protrude upward. The opening end 41 of the guide groove member 4 has its groove wider in width than upper parts 21 of guide piece 2 crossing each other, only at the side of the end D1 of the overhang door body D. The door is constituted such that the opening end 41 of the guide groove member 4 is inserted sideways near a position 22 where the guide pieces 2 cross each other in order to hold the guide pieces 2 at a center part D2 except the edge side D1 of the overhang door body.