To provide an occupant protective airbag device in which an airbag has first and second inflation chambers continuously provided in the longitudinal direction, and development and inflation of the first and second inflation chambers caused by introducing a gas are simultaneously performed when the gas generated in an inflator is introduced in both inflation chambers.

The airbag 26 comprises the first and second inflation chambers 34 and 35 which are continuously provided in the longitudinal direction and inflated by introducing the gas 24 generated in the inflator 25, a first introduction passage 36 which communicates an ejection port of the gas 24 of the inflator 25 with the first introduction passage 36, and introduces the gas 24 to the first inflation chamber 34, and a second introduction passage 37 which is disposed on the imaginary extension line of a downstream end part of the first introduction passage 36, communicates the first inflation chamber 34 with the second inflation chamber 35, and introduces a part of the gas 24 flowing out of the first introduction passage 36 into the second inflation chamber 35. A regulating means 44 for regulating the inflow of the gas 24 flowing out of a downstream end opening 39 of the first introduction passage 36 into an upstream end opening 40 of the second inflation chamber 37 is provided.