Abstract: A hybrid gas generator for an air bag (1) including ignitable gas-producing solid charge (5) placed in combustion chamber, a storage chamber (9) containing a gas (10) and a closed by a first bursting disk (8), a breakable separating wall (13) limiting the combustion chamber, which is connected to a hollow sliding piston (7) to perforate the first bursting disk (8) and a second bursting disk (12) in the separating wall (13) between the combustion chamber and the cavity (14) of the sliding piston (7). In order to construct the generator in a simpler and more economical form, the solid charge (5) is placed in a pyrotechnic cartridge that can be mounted separately the separating wall (13) forms the frontal border of the cartridge (3), a round notch (6) is placed on the round wall of the cartridge (3) serving as predetermined breaking point to break the separating wall (13) and the second bursting disk (12) is formed by a thinning on the separating wall (13).