An airbag device capable of restraining a motor vehicle occupant in a stable position even in an oblique collision. The airbag device includes a bag-shaped main bag inflated and deployed on a vehicle front side of the passenger seat, a bag-shaped center bag inflated and deployed on the inner side of the main bag in the vehicle widthwise direction, and a slit that provides a separation between the main bag and the center bag on the vehicle rear side. A rear end part of the center bag is inclined to gradually protrude rearward in the vehicle as the rear end part is extended upward and protrudes further to the vehicle rear side than at least the main bag.