To provide a device for preventing a sliding door of suspended type from swinging and for keeping the door in the closed state in a stabilized manner with a simple constitution, low cost, and secure operation, which is also applicable to interlocked type of suspension doors.

An arrangement comprises; a suspension door 1 with its upper part held for free movement in opening and closing directions, a guide member 12 which projects from a floor portion where part of the suspension door 1 remains when drawn out and fits into an elongate groove 13 formed in the bottom edge of the suspension door 1, a swing stop pin 11 supported at a floor surface apart from the guide member 12 by a specified distance in the closing direction to be capable of free vertical movement, and a guide member 22 disposed below the swing stop pin 11 and freely slidable in opening and closing dirations of the suspension door 1. The guide member 22 moves together with opening and closing movements of the suspension door 1 with its upper edge in contact with the lower end of the swing stop pin 11, and moves the pin 11 up and down so that its upper end surface is generally flush with the floor surface when the suspension door 1 is in the open position, or fits into the elongate groove 13 formed in the bottom edge of the suspension door 1 when the suspension door 1 is in the closed position.