A chair according to an embodiment of the present invention includes a seat frame, a plurality of legs, a backrest and an armrest. The plurality of legs are rotatably coupled to the seat frame at front and rear portions of the seat frame. The backrest is rotatably coupled to the seat frame at the rear portion of the seat frame. The armrest is rotatably coupled to upper ends of the legs. The armrest includes a movable member and a first elastic member. The movable member is retained inside the armrest and is movable along the armrest. The movable member is rotatably coupled to the backrest. The first elastic member is located inside the armrest and applies an elastic restoration force against the movement of the movable member.