The invention relates to a thermal fogging device using a liquid, comprising: an assembly (3) for producing a pressurized hot gas flow an ejection pipe (5) a first liquid source (7) and a means (9) for injecting a metered liquid flow from the first liquid source (7) into the ejection pipe (5), characterized in that the means (9) for injecting the metered liquid flow comprises a Venturi device (V) having an area (R), the cross-section of which is narrowed and which enables the suction of the metered liquid flow.
