AIRBAG DEVICE

PROBLEM To provide a revolutionary airbag device that can protect an occupant's head from one side, to the front, to the other side. RESOLUTION MEANS The present invention is an airbag device stored in a vehicle seat, the airbag device including: an inflator for generating expansion gas; and an airbag for deploying from near an upper end of the vehicle seat to protect the periphery of the head of an occupant. Furthermore, the airbag includes: a first chamber for protecting one side of an occupant; a second chamber connected to the first chamber and for protecting the front of the occupant's head; a third chamber connected to the second chamber and for deploying from the front of the occupant's head across to the other side of the occupant; and a fourth chamber connected to the third chamber and for deploying at the other side of the occupant.