Method for thermal conversion of a substance mixture into particles in a reactor chamber, comprising the steps: - providing the substance mixture in the form of a solution, a suspension, a dispersion or an emulsion of at least one starting substance of the particles, - generating a fog of droplets of the substance mixture in at least one carrier gas, - introducing the fog into the reactor chamber as an educt current by means of a carrier gas current, - introducing a hot gas current into the reactor chamber and mixing the educt current and the hot gas current for heating the educt current to a starting temperature which is at least necessary for the thermal conversion of the at least one starting substance, - guiding the educt current and the hot gas current, as a reaction current having an average current velocity, along a reaction section directed through the reactor chamber, the reaction section having a beginning of the section (3.1) and an end of the section (3.2), wherein the beginning of the section (3.1) of the reaction section is given by the location of the mixing of the hot gas current with the educt current, - supplying the reactor chamber with a cooling current and mixing the cooling current with the reaction current for cooling the reaction current to a target temperature within a cooling duration, wherein the end of the section (3.2) of the reaction section is given by the location at which the target temperature is reached, and - collecting the produced particles, characterized in that - the hot gas current is indirectly heated in a hot gas supply serving to supply the hot gas current to the beginning of the section (3.1), - the reaction current is continuously guided along the reaction section and - the average current velocity is adjusted in such a way that the reaction current is guided along the reaction section within a predetermined reaction duration, which is selected to be at most 2 seconds, so that the heating of the educt current, the thermal conversion of the at least one starting substance into the particles and the cooling of the particles to the target temperature are carried out within the reaction duration. - providing the substance mixture in the form of a solution, a suspension, a dispersion or an emulsion of at least one starting substance of the particles, - generating a fog of droplets of the substance mixture in at least one carrier gas, - introducing the fog into the reactor chamber as an educt current by means of a carrier gas current, - introducing a hot gas current into the reactor chamber and mixing the educt current and the hot gas current for heating the educt current to a starting temperature which is at least necessary for the thermal conversion of the at least one starting substance, - guiding the educt current and the hot gas current, as a reaction current having an average current velocity, along a reaction section directed through the reactor chamber, the reaction section having a beginning of the section (3.1) and an end of the section (3.2), wherein the beginning of the section (3.1) of the reaction section is given by the location of the mixing of the hot gas current with the educt current, - supplying the reactor chamber with a cooling current and mixing the cooling current with the reaction current for cooling the reaction current to a target temperature within a cooling duration, wherein the end of the section (3.2) of the reaction section is given by the location at which the target temperature is reached, and - collecting the produced particles, characterized in that - the hot gas current is indirectly heated in a hot gas supply serving to supply the hot gas current to the beginning of the section (3.1), - the reaction current is continuously guided along the reaction section and - the average current velocity is adjusted in such a way that the reaction current is guided along the reaction section within a predetermined reaction duration, which is selected to be at most 2 seconds, so that the heating of the educt current, the thermal conversion of the at least one starting substance into the particles and the cooling of the particles to the target temperature are carried out within the reaction duration.