Abstract: A gas generator contains hydrazodicarbonamide serving as a reducing agent, oxoacid salt serving as an oxidizing agent, and a combustion controller which is catalytic or combustible. As a combustible combustion controller, boron, and zirconium are preferred. The gas generator includes a flame coolant containing at least one compound selected from the group consisting of hydrates of metal sulfates, hydrates of metal nitrates, hydrates of metal carbonates, metal hydroxides, and hydrates of metal hydroxides in which the metal moieties are selected from the III, IV, V, and VI Period metal of the Periodic Table. As a flame coolant, magnesium hydroxide is preferred.