To suppress the projection amount of legs during no use as wall as to increase the stability of the chair during use.

At a leg base 23, four legs 40 are radially provided with the interval of 90° on a pin 36 as a center so that the legs are pivotal inwardly and outwardly. The legs 40 are elastically supported to be closed by a rubber member 50 fitted into an attaching groove 51. When load is applied in the arrow A direction, the leg 40 presses the rubber member 50 onto the pin 36 as a center and moves in the arrow B direction, and a caster 42 in contact with a floor 43 moves outwardly to increase the stability of a chair C. When the load is released, the rubber member 50 is elastically restored, the leg 40 moves to the center position, and the projection amount of the end of the leg is decreased, resulting in that stumbling is prevented.