Gas generator

The gas generator (10) comprises a housing (12) with gas stream outlet holes (22,28), at least one of which is sealed off moisture-tight by a destructible insulating film (24) in the gas generator's non-activated state. The film has varying thickness created by at least one thermally insulating film layer of synthetic material which lies over a base layer. The thermally insulating layer lies on the side of the insulating film which faces the gas stream. The base layer consists of metal and is of constant thickness.