SIDE AIRBAG DEVICE FOR AUTOMOBILE

Lifting up of a side airbag toward a vehicle upper side when there is a side collision is suppressed or prevented. In a side airbag (22), a tether (46) is provided that divides the side airbag (22) into a lower chamber (56) and an upper chamber (58). The tether (46) is attached in an attitude that, viewed from a vehicle forward side, is inclined such that a vehicle width direction inner side thereof is higher than the vehicle width direction outer side. A gas jetting aperture (34) is formed at a lower end portion of a diffuser (26) of a gas jetting unit (20). The gas jetting aperture (34) is disposed in the lower chamber (56) and is oriented toward a lower face (46B) of the tether (46). Therefore, during a process of expansion of the side airbag (22), gas strikes the lower face (46B) of the tether (46), then strikes portions that have not yet unfolded, and flows downward.