A gas generator, comprising a housing (1), a combustion chamber (2) formed in the housing (1), filled with gas generating agent (3) producing hot gas by burning, and having a filter material (4), an ignitor (5) fitted into the housing (1) and igniting for burning the gas generating agent (3) in the combustion chamber (2), and a gas discharge hole (6) formed in the housing (1) and allowing the inside of the housing (1) to communicate with the outside through the combustion chamber (2) and a gas flow passage (S), the gas flow passage (S) further comprising coolant (21).
