Abstract: The invention solves the problem of production of inert gases by way of liquid fuel combustion and diffusion of combustion products with water in a device having small overall dimensions and ensuring to obtain and pump large quantities of gases with the oxygen content well below 2% of the volume as well as minimum content of unburnt fuel particles and, furthermore, devoid of dissociation products. The device consists of a turbo-compressor and tightly connected chambers for oxygen pre-reduction, fuel atomizers, combustion, mixing, after burning and diffusion cooling. The pre-reduction chamber preferably has four flame tubes with fuel injectors and sparking plugs and the chamber of the fuel atomizers in equipped with two circumferential rows of atomizers.