AIRBAG DEVICE

It is aimed to reduce a weight of a configuration for suppressing an airbag from spreading in a radial direction as much as possible. Provided is an airbag device (20) installed into an instrument panel (110) including a lid portion (12) configured to be torn and a lid-side peripheral wall portion (14) provided to stand on an outer periphery of the lid portion (12). The airbag device (20) includes: an inflator (22); an airbag (30) so as to be inflated and deployed in a bag shape by the gas introduced from the inflator (22); and an outer bag (50) formed of a sheet-like member to be sewn into a three-dimensional shape having an outer-bag-side bottom (52) and an outer-bag-side peripheral wall portion (54) provided on an outer periphery of the outer-bag-side bottom (52), the outer-bag-side bottom (52) being secured to the inflator (22), the outer-bag-side peripheral wall portion (54) surrounding the folded airbag (30) and being disposed so as to be sandwiched between the airbag (30) being inflated and deployed and the lid-side peripheral wall portion (14).