Abstract: Longitudinally continuous sheets 11, 12, 31, 32 as a plurality of components are continuously supplied in a longitudinal direction to lie one upon another, and adhered at predetermined spots to form an article containing portion 2 having a space for an article and an air passageway 3 having a space continuing to the space of the article containing portion 2. Said sheets are a frontal sheet 11, a rear sheet 12 which is equal to the frontal sheet 11 in breadth, i.e. the transverse side dimension of the sheets, at least one valve body sheet 31 disposed between said both sheets 11 and 12 and made smaller than the sheets 11, 12 in breadth and base members 32 disposed between at least one of the frontal and rear sheets 11, 12 and the valve body sheet 31 and made smaller than the valve body sheet 31 in breadth.