Abstract: The invention relates to the deposition of nanoparticles from the gas phase of the a thermal plasma of a gas discharge and the subsequent attachment of said nanoparticles to the substrate particles. The invention can be used for increasing the flowability of solid bulk material. Particularly the pharmaceutical industry utilizes numerous intermediate and final products in the form of powders which cause processing problems because of the poor flowability thereof. With fine-grained materials, undesired adhesive effects occur foremost because of Van der Waals' forces. Said effects can be reduced by applying nanoparticles to the surface of the material that is to be treated. The invention is characterized by a combined process in which the nanoparticles are produced and are attached to the substrate surface. Using a non-thermal plasma additionally makes it possible to treat temperature-sensitive materials that are often used in the pharmaceutical industry.