The invention relates to a gas generator (10) for use in a safety device for motor vehicles comprising a housing and a propellant (4) contained in a combustion chamber (25) of the housing for generating a pressurized gas, the housing comprising a first housing part (40) and a second housing part (30) at least partly surrounded by the first housing part (40) and at least one igniter (6) for igniting the propellant (4), and an annular filter (50) surrounding the combustion chamber (25) in which the propellant (4) is located. The filter (50) comprises a peripheral portion (52) and a radial portion (51), the radial portion (51) serving as filling body for the propellant (4) in the combustion chamber (25).