INFLATOR

An inflator suitable for a curtain air bag is provided. The inflator has two igniters 36 and 46 and gas discharge ports 34 formed on one end side. A first rupturable plate 38 is broken by activation of the first igniter 36 and pressurized gas is discharged from gas discharge ports 34, and a second rupturable plate 48 is broken by activation of a second igniter 46 and combustion gas is discharged from gas discharge ports 34. Accordingly, the air bag can be inflated instantly and inflation can be maintained.