A head protecting airbag device comprises an airbag and a gas feeder member. The airbag includes a main portion, an inlet port and a plurality of mounting portions. The inlet port is connected above an intermediate pillar portion to a gas feeder so as to admit inflating gas downward into a gas receiving portion of the main portion. The mounting portions are composed of a vicinity mounting portion arranged close to the inlet port, and general mounting portions. A recess is formed between the vicinity mounting portion and the inlet port. This recess substantially enlarges the length of the outer peripheral edge of the vicinity mounting portion facing the inlet port and the outer peripheral edge of the inlet port facing the vicinity mounting portion, thereby increasing the possible separation of the vicinity mounting portion and the inlet port.