An airbag device for a vehicle has a base (10) with an inflator (9) attached to it for generating gas when the vehicle collides with something, and the airbag (2) itself. This has a main opening so that the inflator can be inserted inside it and another one for the electrical connection for the inflator to the wiring harness. A different region from the one containing the main opening is inserted between the inflator and the base. The main opening acts as a ventilation hole to allow the gas generated within the bag to escape. The inner diameter of the second opening is smaller than the outer diameter of the inflator.
