Provided is an airbag device including an airbag body having a first base fabric and a second base fabric, wherein the first base fabric and the second base fabric have an outer circumferential section and an outer circumferential section that are joined to each other while overlapping each other, a first base fabric joining section formed by joining a plurality of predetermined portions, spaced apart from each other in a circumferential direction of the first base fabric is provided on an outer circumferential side of the first base fabric, and a second base fabric joining section formed by joining a plurality of predetermined portions, spaced apart from each other in a circumferential direction of the second base fabric is provided on an outer circumferential side of the second base fabric.