Gas generator

A gas generator, comprising:

• an ignition device chamber arranged at a first end opening of a cylindrical housing;
• a diffuser portion provided with a gas discharge port and arranged at a second end opening opposite to the first end opening in a longitudinal axial direction of the cylindrical housing;
• a pressurized gas chamber arranged between the ignition device chamber and the diffuser portion;
• a first rupturable plate closing the first end opening between the ignition device chamber and the pressurized gas chamber;
• a second rupturable plate closing the second end opening between the pressurized gas chamber and the diffuser portion;
• an igniter which includes an ignition agent, and a molded article of a gas generating agent being accommodated in the ignition device chamber;
• a gas which serves as a gas source being charged in the pressurized gas chamber;
• and
• an amount A (J/msec) of energy generated per unit time from the molded article of the gas generating agent charged in the ignition device chamber,
• an amount D (J/msec) of energy generated per unit time from the igniter,
• a cross-sectional area B (cm2), orthogonal to the longitudinal axial direction of the cylindrical housing, of the pressurized gas chamber at a portion proximate to the ignition device chamber, and
• a density C (g/cm3) of the gas charged in the pressurized gas chamber satisfying
• an energy control factor represented by the following equation (II):
• (A+D)/B×C=430 to 580 (II).