Airbag device and passenger protection device

An airbag device, comprising:

• an inflator that generates gas during a vehicle collision;
• and
• an airbag that is supplied with gas generated by the inflator, and that inflates and deploys from a seat rear side of a vehicle seat toward a seat front side via a seat upper side,
• wherein, in an inflated and deployed state, the airbag includes:
• a pair of front-rear chambers extending in a seat front-rear direction via left and right sides of the head of a passenger seated in the vehicle seat, and
• an airbag body that is in communication with the pair of front-rear chambers, that is disposed at a seat front side of the passenger between the pair of front-rear chambers, and that is compression deformed in a state supported by the pair of front-rear chambers during restraint of the passenger, and
• wherein the airbag is configured such that, in an inflated and deployed state, entry of at least the head of the passenger into a gap between the front-rear chamber and the airbag body is suppressed during a latter half of restraining the passenger.