Curtain airbag and manufacturing method therefor

A curtain airbag attached to a vehicle body, that expands and deploys by a gas supplied from an inflator, comprising:

• a first surface;
• a second surface;
• a first region along a lower edge;
• a second region adjacent that is above the first region with a first fold line as a boundary;
• a third region that is adjacent above the second region with a second fold line formed as a boundary on an opposite side of the first fold line across the second region;
• wherein
• the first region is in a condition folded back at the first fold line so as to face a first surface side of the second region,
• the second region is in a condition folded back at the second fold line such that the folded back first region is sandwiched between the second region and the third region,
• the third region is in a condition rolled upward on a second surface side, with the rolling starting from the second fold line, and
• the first region and the second region are provided to the inward side of the third region when stored and attached to the vehicle body.