Abstract: An airbag device is formed of a retainer having a center opening, an air bag, and at least one inflater fixed to the retainer. The air bag includes an outer bag having an outer bag opening, and an inner bag arranged inside the outer bag and having an inner bag opening. The peripheries of the outer and inner bag openings are directly or indirectly fixed to the retainer so that the inner bag communicates with an outside through the outer bag opening and the center opening. The inflater has a main body containing a gas generating agent therein and faces a space between the outer and inner bags to directly supply gas to the space when the inflater is actuated. When the gas is supplied to the space between the outer and inner bags, air is inspired into the inner bag through the center opening.