Airbag apparatus

An airbag apparatus comprising an airbag that is formed into a bag shape by sewing a plurality of fabric portions together at peripheries thereof, wherein the airbag includes:

• a periphery sewn portion formed by the sewing;
• a margin located outward of the periphery sewn portion;
• and
• an inflation portion surrounded by the periphery sewn portion, wherein
• the inflation portion is adapted to be inflated by being supplied with inflation gas and has a center,
• the periphery sewn portion has two terminals separated from each other, and the terminals are formed by leaving sections of the peripheries of the fabric portions unsewn,
• the airbag further includes:
• a pair of surrounding sewn portions, each of which is formed by sewing parts of the fabric portions that surround one of the terminals of the periphery sewn portion;
• a vent hole located between the terminals of the periphery sewn portion, wherein the vent hole has an opening that allows inflation gas from inside the inflation portion to be discharged, and the opening is defined by vent hole defining sections, each of which is located in one of the surrounding sewn portions, the vent hole defining sections facing each other and being closest to each other;
• and
• a pair of position determining portions, each of which is located close to one of the surrounding sewn portions, wherein
• each of the surrounding sewn portions is formed in place with reference to the corresponding position determining portion, and
• the position determining portions are each formed in the margin and farther away from the vent hole in a circumferential direction of the margin than the vent hole defining section of the corresponding surrounding sewn portion.