Provided is an air bag device to which an inflator can be easily attached and fixed. This air bag device is provided with: an inflator 12 that generates gas; an air bag 16 that is expanded by the gas generated by the inflator 12; a retainer 14 having an insertion hole 14a through which the inflator 12 is inserted; a bag ring 20 that attaches the air bag 16 to the retainer 14; and a spring part 30 that fixes the inflator 12 inserted through the insertion port 14a.
