AIRBAG DEVICE

An airbag that prevents heavy interference with the head of an occupant during expansion and deployment even when the occupant is not seated in a vehicle seat in a regular position. [0002] An airbag device 11, including an airbag 12 and an inflator 6 for supplying gas to the airbag 12. The airbag 12 is positioned to the sides of the center in the left-right direction of the vehicle seat 2 and has a pair of chambers 1a physically coupled by a coupling section 12a that deploy forward of the occupant 3 when expansion and deployment are complete. The pair of chambers 1a are respectively independent during expansion and deployment and expand and deploy frontward from both the left and right sides of the vehicle seat 2, having side protecting chambers 1ab that cover at least the side sections 3b of the occupant 3. The side protecting chambers 1ab are coupled by coupling sections 12a positioned to the sides of the center in the left-right direction of the vehicle seat 2, and the coupling section 12a is thinner than the side protecting chambers 1ab at least during initial expansion and deployment.