Hitherto, various technologies of protecting a rider by an airbag device mounted to a motorcycle have been known. For example, a technology used in a motor-bicycle for holding an airbag by a securing member which is used to connect an airbag device and a vehicle body (vehicle frame) and which stretches along with the air bag when the airbag is deployed is publicly known (refer to, for example, Japanese Unexamined Patent Application Publication No. 10-35564). According to the technology, even if the vehicle body has an open structure in all directions like a motorcycle, a rider can be restrained by the airbag.