Abstract: In an airbag device, a decorative member is prevented from being scattered with a simple structure at the time of expansion of an airbag. That is, a concave part of the airbag cover (50) on which the decorative member is mounted is connected to an unmoved connection member while freely separable from other portions at the time of expansion of an airbag. To that end, there are formed, on the inner faces of the airbag cover (50), a circular tear line Lc for partitioning the concave part (52) and a plurality of tear lines L1˜4 extending outward from the tear line Lc in the radial direction thereof for forming each of opening pieces (50a). Further, attachment pieces (50b) of respective opening pieces (50a) are fastened to plastic deformable attachment parts of a base plate by screws. With this structure, the concave part of the airbag cover can be immovably held at the time of spread of the airbag.