The present invention relates to an airbag device for a vehicle. The airbag device comprises: an airbag cushion which is formed in a shawl shape and deployed toward both sides of a passenger so as to wrap and restrain the entire upper body around both shoulders of the passenger when a vehicle collides; and an inflator for generating gas and supplying the gas to the airbag cushion in response to an impact detection signal when the vehicle collides. Accordingly, when a vehicle collides, the shawl-shaped airbag cushion installed on the back of a seat is inflated and deployed to restrain the both sides and front area of the upper body of a passenger around both shoulders of the passenger, thereby safely protecting the passenger.