A head protection airbag according to the invention includes: a shielding main body portion which is manufactured by double weaving, is configured to have a substantially rectangular plate shape when the shielding main body portion is flatly deployed so that a vehicle inside-facing wall and a vehicle outside-facing wall overlap with each other, and covers a window on the inside when the inflation is completed; a plurality of mounting portions which protrude upward from an upper edge of the shielding main body portion and mount the upper edge of the shielding main body portion on an upper edge of the window; and a connection port which has a substantially tubular shape, protrudes upward from the upper edge of the shielding main body portion and allows an inflow of inflation gas into the shielding main body portion. The mounting portions and the connection port are separate from the double-woven shielding main body portion and are connected to the shielding main body portion.