An airbag apparatus includes an airbag that deploys and inflates while being unfolded from an accommodating portion, when inflating gas flows into the airbag; and a regulating member that is able to regulate the deployment and inflation of an airbag. The regulating member is flexible, and includes a temporary holding portion that releasably and temporarily holds a folded portion that is a part of the airbag; an attachment portion that is attached to the accommodating portion; and a connecting piece portion that connects the attachment portion and the temporary holding portion. The temporary holding portion includes a base portion that is continuous with the connecting piece portion, and a cover portion that forms a holding concave portion for temporarily holding the folded portion, and is connected to the base portion. An opening for releasing the folded portion is provided at an inner circumference of a non-connected release edge.