A vehicle seat includes a seat back frame, an elastic installation supporting member installed in the seat back frame, and an airbag within a seat back, the vehicle seat causing the airbag to inflate and develop within the seat back. An inflator is attached to the seat back frame. An inflation and a development of the airbag in the seat back due to an operation of the inflator allows the airbag to elastically support an upper body of a seated person and to elastically receive an impact force which is applied to a rear of the seat back.