An airbag module for use in a motor vehicle is manufactured by first to third steps. In the first step, the airbag is folded into a predetermined configuration, and in the second step, an entire external surface of the airbag, in an initially folded condition obtained in the first step, is wrapped in a bag-shaped film forming member. The bag-shaped film forming member includes a plurality of resin layers formed in a layer-stack manner with regard to a film cross-sectional direction. In the third step, the initially folded airbag is housed in the airbag-housing member in a condition wherein the airbag has an airbag volume reduced to less than the airbag volume at a time of being initially folded, by a compression force applied to the bag-shaped film forming member.
