AIRBAG APPARATUS

An airbag apparatus includes an inflator, which generates inflation gas, and an airbag, which is supplied with the inflation gas from the inflator. The airbag is arranged in the seat back of a front seat. The airbag includes a lower inflation portion and an upper inflation portion. The lower inflation portion is inflated by the inflation gas only inside the lower part of the seat back. The upper inflation portion is arranged inside the seat back and above the lower inflation portion. The upper inflation portion is inflated above the lower inflation portion by the inflation gas, breaks the covering, which constitutes the outer shell of the seat back, and is inflated outside the seat back through the broken part of the covering.