An airbag device for stably controlling gas discharge and restraining an occupant in a vehicle. A first vent hole, for discharging gas from the airbag, is formed in a portion of the airbag, and one end of a tubular discharge restricting member is connected to the first vent hole. Once the airbag is inflated and deployed to a predetermined extent or more, the first vent hole is closed by the discharge restricting member. Prior to deployment, at least a portion of the airbag is folded in a bellows shape to form a folded portion. The connecting portion between the discharge restricting member and the first vent hole is positioned in a trough portion of the folded portion. The other end of the discharge restricting member is stored so as to face the outer side and not to protrude beyond an outer edge of the folded portion.