This air cell cushion has a pair of side air cells (20) provided so as to extend upwardly from the upper surface side of the base member (30) at the both end sides in the lateral direction of the base member (30). The side air cells (20) have the larger front-rear direction size than that in the lateral direction thereof. Also, each side air cell (20) is configured so as to inflate outside in the lateral direction. By this, in a case in which the side air cells (20) are facing to the armrests of the wheel chair, when the side air cells (20) are inflated outside in the lateral direction, the outer side surfaces of the side air cells will abut against or become adjacent to the armrests.
