An airbag cushion, which expands and deploys between adjacent seats in a passenger compartment, comprising a top panel and bottom panel that are separated and face each other vertically when deployed, side panels connecting the edges of the top panel and the bottom panel, a protruding part that protrudes upward from the top panel, a cylindrical inflator attached along the inner surface of the side panel on the side of the protruding part is stowed in a folded state by overlaying the top panel and the side panel provided with the attachment part of the inflator, and lining up a first roll part which is the protruding part rolled up, a fold-back part which is the first side part folded back to cover the attachment part of the inflator, and a second roll part on top of the top panel with the second roll part in the center.