GAS GENERATOR

A gas generator includes: an ignition device chamber arranged at one end opening of a housing; a diffuser portion provided with a gas discharge port and arranged at another end opening; a pressurized gas chamber arranged between the ignition device chamber and the diffuser portion; a first rupturable plate closing the one end opening between the ignition device chamber and the chamber; a second rupturable plate closing the other end opening between the chamber and the diffuser portion; an igniter and a molded article of a gas generating agent accommodated in the ignition device chamber; a gas charged in the chamber; and an amount A (J/msec) of energy generated per unit time by the gas generating agent, a cross-sectional area B (cm2) of the chamber at a portion proximate to the ignition device chamber, and a density C (g/cm3) of the gas satisfy A/B×C=320 to 490.