An airbag device for straddle type vehicles is provided with: an airbag module in which a holding box that stores an airbag functions as a case; and an airbag control unit that controls said airbag module. The airbag module is provided with the holding box that is disposed immediately in front of a rider's seat, a lid that closes the opening of the holding box, and a hinge that functions as a rotary fulcrum for the lid when the airbag inflates, and that is positioned on the rear side, with respect to the vehicle, of the lid. A linking mechanism for restricting the opening angle of the lid is provided between the lid and the holding box.