Air bag in use for head protection air bag device

An air bag in use for a head protection air bag device in which said air bag, while being folded, is stored in an upper fringe of openings on a cabin-inside side of a vehicle, said air bag comprising:

• a gas inflow part for flowing inflation gas;
• a gas passage extending forwardly from said gas inflow part;
• a front-seat inflation chamber located at a position near a side of a front seat for receiving the inflation gas;
• a rear-seat inflation chamber located at a position near a side of a rear seat for receiving the inflation gas, said front- and rear-seat inflation chambers being disposed below said gas passage through respective inflow ports formed in upper parts of said front- and rear-seat inflation chambers to allow the inflation gas to flow into said front- and rear-seat inflation chambers;
• and
• a partitioning part dividing said gas passage from said rear-seat inflation chamber to thereby define said inflow port of said rear-seat inflation chamber, said partitioning part comprising a beginning part and a linear part linearly slanting downwardly from said beginning part in a frontward direction and a rear-side peripheral edge of said inflow port of said rear-seat inflation chamber is positioned at a forward end of said linear part;
• wherein said inflow port of said rear-seat inflation chamber is opened in a direction substantially orthogonal to an axial direction of said gas passage, and a front-side peripheral edge of said inflow port is disposed to be higher than said rear-side peripheral edge of said inflow port.