A first airbag apparatus of the present invention has an airbag module, which includes an airbag and an inflator, and a displacement mechanism, which displaces the airbag module. The displacement mechanism displaces the airbag module from an original position to a predetermined position when a collision of the vehicle is predicted and displaces the airbag module from the predetermined position to the original position when the predicted collision is avoided. A second airbag apparatus of the present invention has the airbag module and the displacement mechanism, which displaces a support member. The support member displaces the airbag from the original position to the predetermined position before the airbag is deployed. The deployed airbag is supported between the support body that is displaced to the predetermined position and an occupant.