A curtain airbag for mitigating vehicle occupant ejection. The curtain airbag is stored in the upper portion of a side face section in the interior of a vehicle and is inflated and deployed along the side face section. The curtain airbag includes a front chamber partitioned at the frontmost side of an inflation region. The front chamber is inflated and deployed overlapping a divider-bar that separates a side window from a front pillar window.