AIRBAG DEVICE AND VEHICLE SEAT

The present invention is an airbag device equipped in a vehicle seat having a seat cushion forming a seat surface and a seatback forming a backrest, containing: an inflator; and an airbag that is stowed in the seatback and deployed by expansion gas discharged from the inflator. The airbag includes a pair of left and right side chambers that deploy from the side parts of the seatback forward and an upper chamber that is provided continuously with the side chambers and deploys above the head of the occupant. The airbag, from a state of being spread out before stowing, is rolled or folded and compressed in a long rod shape in a direction intersecting a longitudinal direction. The location corresponding to the upper chamber of the long rod-shapedairbag is stowed in a stowing part at the rear surface of the headrest at the upper part of the seatback.