[Problem] To provide a side airbag apparatus that improves passenger restraining performance and maintains a form at the time of housing.
[Solution] A side airbag apparatus 100 includes a frame-side plate portion 114 of a seat 102, and an airbag module 106 attached to the frame-side plate portion 114. The airbag module 106 includes a bracket 112, an inflator 110, an airbag cushion 108, and a soft cover 116 that is wrapped around the bracket 112 and the airbag cushion 108 in a housing form. The bracket 112 includes a through-hole 128 through which a stud bolt 118 extending from the inflator 110 passes, and a hook 130 provided at predetermined location on the front side of the frame-side plate portion 114. The soft cover 116 includes a bolt anchoring hole 120 to which the stud bolt 118 is hooked, and a hook anchoring hole 122 to which the hook 130 of the bracket 112 is hooked.