An airbag device for restraining an occupant even during an oblique collision and suppressing head injury values. An airbag device 100 includes: a passenger bag 112 which deploys on a front side of a passenger seat 104; a center bag 114 which deploys on an inner side in a vehicle width direction; a slit 128 which separates the passenger bag 112 and the center bag 114 from each other on a vehicle rearward side; and a tether belt 122 which which is connected to a first connecting part 124 on the center bag 114 and a second connecting part 126 on the passenger bag 112. The tether belt 122 is tensioned as the passenger bag 112 and the center bag 114 expand and deploy, and the center bag 114 restrains a side of the occupant head E1a while being supported by the tether belt 122.