Abstract: The invention relates to a device for generating a fog, characterized in that it comprises: a) a first closed vessel (1) kept at temperature and filled with a mixture having such a vapor pressure curve that pressure can be generated by varying the temperature of the mixture; b) a second closed vessel (2, 2', 2") with a heat exchanger kept at a higher temperature; c) a pipe (7) with a valve (8) connecting the mixture from the first vessel to the second vessel (2, 2', 2"); d) an outlet (16, 16') in the wall of the second vessel (2, 2', 2") for distributing the fog generated under pressure in this latter vessel into the environment.