A multi-pulse gas generator includes a pressure vessel, an outer propellant arranged in the pressure vessel and which has a tubular shape, an intermediate propellant arranged inside the outer propellant and which has a tubular shape, an inner propellant arranged inside the intermediate propellant and which has a tubular shape, an internal structure arranged inside the inner propellant and fixed to the pressure vessel, a first barrier membrane arranged between the outer propellant and the intermediate propellant so as to isolate the outer propellant and the intermediate propellant from each other, and a second barrier membrane arranged between the intermediate propellant and the inner propellant so as to isolate the intermediate propellant and the inner propellant from each other. The outer propellant is supported on its outer surface by the pressure vessel. The inner propellant is supported on its inner surface by the internal structure.