AIRBAG DEVICE

An airbag device includes: an inflator generating gas; a bag-shaped airbag configured to be inflated and deployed, the airbag having a vent hole through which the gas is discharged; and a gas flow adjustment member including: a gas receiving part covering the vent hole; an opening edge portion formed at a portion of an outer peripheral edge of the gas receiving part; and an attachment edge portion for attaching the outer peripheral edge except the opening edge portion to the airbag, the attachment edge portion having an opposite portion which is opposite to the opening edge portion, in which the gas flow adjustment member is provided with at least one pleat portion formed such that a fold extends from the opening edge portion toward the opposite portion, and the at least one pleat portion is configured such that the fold is kept folded at the attachment edge portion.