An airbag device according to the present invention includes an airbag folded and housed in the shape of folded-up body, and an airbag wrapping member for keeping the folded-up configuration of the airbag. The folded-up body is formed by bringing both ends of the airbag close to a base line, such that the folded-up body is symmetric with respect to the base line. The wrapping member includes a breakable portion in a region above the base line. The breakable portion includes a plurality of apertures each of which is located across the base line as to extend toward both sides from the base line, and connecting portions for connecting adjacent apertures into a larger opening upon breakage. The connecting portions disposed by the side of both ends of each of the apertures are located in opposite sides of the base line. The wrapping member further includes two cut-out portions in edges of a cover portion in a direction along the base line.