SIDE AIRBAG DEVICE AND METHOD FOR MANUFACTURING AIRBAG USED IN SAME

The present invention is a side airbag device stowed in a seatback of a vehicle seat, comprising: an inflator arranged on the occupant side of a side frame which is positioned on a side part inside the seatback, that generates expansion gas, and an airbag which expands due to said expansion gas and protects the occupant seated in the vehicle seat. The airbag includes a main chamber that deploys toward the front of the seatback, and a pre-chamber that houses the inflator inside and is connected to the occupant side of the main chamber. Furthermore, an integral joint without gaps is formed by sewing between at least the front edge part of the pre-chamber and the main chamber.