Abstract: A hybrid gas generator includes a pyrotechnic gas generator joined to a high-pressure vessel which is sealed with a sealing disk composed of a substance which chemically reacts with propellant gas produced in use so that the sealing disk is opened with an advantageously reduced acoustic pressure. The propellant gas is chemically reactive and is produced from a propellant composition which is present in a surplus amount and which is composed of a propellant which is oxidizable and at least one oxidant for oxidizing the propellant. The propellant gas attacks the sealing disk chemically and thermally, and continuously burns through it to release the gas from the high-pressure vessel into a mixing chamber in the pyrotechnic gas generator.