A system comprising an air nozzle and a self-standing pouch in which a first side-surface film, a second side-surface film, and a bottom film sandwiched therebetween are joined together, peripheral portions thereof are sealed to form a storage part, and the bottom film serves as a lower bottom surface of the storage part, the self-standing pouch comprising: a non-sealed region provided in a side edge portion corresponding to a region where peripheral portions at side ends of the first side-surface film and the second side-surface film are sealed, the non-sealed region being a region not sealed over a predetermined length in a top-bottom direction, and an opening provided at a position near an upper end of the non-sealed region, the opening being formed penetrating through at least one of the first side-surface film and the second side-surface film, wherein the air nozzle comprises an air blowout hole and has a tip surface, the non-sealed region includes an air filling portion which takes therein, through the opening, air blown out from the air blowout hole of the air nozzle having the tip surface, characterized in that the tip surface is disposed at a position a predetermined distance apart from the opening and the air filling portion is not sealed within a predetermined radius larger than a radius of the air nozzle from a center of the opening such that, when air is blown from the air blowout hole at the center of the tip surface of the air nozzle and the air filling portion expands due to an increase in an internal pressure, a part near the opening is closely adhered to the tip surface of the air nozzle, either the opening is at least one straight line slit having a length longer than a diameter of the air blowout hole of the air nozzle and shorter than a diameter of the air nozzle and penetrating the first side-surface film and/or the second side-surface film, or the opening is an arc-shaped slit or a hole having a diameter larger than a diameter of the air blowout hole of the air nozzle and smaller than a diameter of the air nozzle, wherein the arc-shaped slit or the hole penetrates the first side-surface film and/or the second side-surface film. a non-sealed region provided in a side edge portion corresponding to a region where peripheral portions at side ends of the first side-surface film and the second side-surface film are sealed, the non-sealed region being a region not sealed over a predetermined length in a top-bottom direction, and an opening provided at a position near an upper end of the non-sealed region, the opening being formed penetrating through at least one of the first side-surface film and the second side-surface film, wherein the air nozzle comprises an air blowout hole and has a tip surface, the non-sealed region includes an air filling portion which takes therein, through the opening, air blown out from the air blowout hole of the air nozzle having the tip surface, characterized in that the tip surface is disposed at a position a predetermined distance apart from the opening and the air filling portion is not sealed within a predetermined radius larger than a radius of the air nozzle from a center of the opening such that, when air is blown from the air blowout hole at the center of the tip surface of the air nozzle and the air filling portion expands due to an increase in an internal pressure, a part near the opening is closely adhered to the tip surface of the air nozzle, either the opening is at least one straight line slit having a length longer than a diameter of the air blowout hole of the air nozzle and shorter than a diameter of the air nozzle and penetrating the first side-surface film and/or the second side-surface film, or the opening is an arc-shaped slit or a hole having a diameter larger than a diameter of the air blowout hole of the air nozzle and smaller than a diameter of the air nozzle, wherein the arc-shaped slit or the hole penetrates the first side-surface film and/or the second side-surface film.