Patent attributes
A belt-like protruding portion 34d extending longitudinally is provided on an air bag cover 34 which covers a folded air bag 21. In the event that the air bag 21 is twisted when the air bag 21 is mounted on a vehicle body, a longitudinal dimension of the air bag 21 is contracted largely, whereby an interval between adjacent mounting portions 21a is decreased, thereby the fixing of the air bag 21 being disabled. As a result, the fixing of the air bag 21 in the twisted state is prevented assuredly, and the smooth deployment of the air bag 21 is enabled. A rod-like twist preventing member may be fixed longitudinally along the folded air bag 21 instead of the belt-like protruding portion 34d.