plasma zone or after the plasma zone to bring the gaseous monomer into a chemically reactive state and to a homogeneous chemical reaction with the result that nanoparticles form from the gas phase owing to chemical deposition and that a treatment zone is present through which a substrate particle and or substrate particle gas stream is guided under the influence of the gas flow and or the gravitational force and in which the formed nanoparticles attach to the surface of the substrate particles due to the collision of the two types of particles a first preferred embodiment of the apparatus is characterized in that a first guiding element is arranged preferably in the form of a tube in which the substrate particles are guided in the sense of a drop tube or of an ascending tube and in that a second guiding element which is arranged preferably substantially at right angles to the first guiding element and opens into this first guiding element preferably in the form of a tube is present in which second guiding element the gas stream with the monomers is guided and in which second guiding element the anisothermal plasma zone is arranged such that substantially directly after this plasma zone the nanoparticles which are formed there in the gas stream attach to the surface of the substrate particles by way of the collision of the two types of particles in the treatment zone the treatment of fine grained substances which are flowable only to a limited extent or not at all in anisothermal plasmas with the aid of chemical deposition of nanoparticles from the.