Nanopowder is a mass of dry nanoparticles whose size ranges from 1 to 100 nm in at least one dimension. Nanopowders are divided into four main groups: 1) nanopowders of metals and semiconductors (e.g, titanium, iron, copper, aluminum, gold, silver, silicon), 2) nanopowders of oxides (oxides of aluminum, iron, zinc, zirconium, etc.) 3) powders of carbon and carbon nanotubes and fullerenes, 4) nanopowders of carbides, nitrides, silicides and other compounds used for the formation of oxygen-free ceramics, coatings and other products. Nanopowders have a wide range of applications. They are used in production of electronic and optical devices, pharmaceuticals and medical products, cosmetics, building materials, coatings and other goods. Nanopowders are used in mechanical engineering (for instance, hardening different surfaces), and in alternative energy (solar cell production). At present the following technologies and methods of nanopowder production are used: - deposition of powders from solutions onto substrates; - gas-phase synthesis, which means decomposition of various compounds and condensation of metal and alloy vapors under controlled temperature in an inert-gas atmosphere with low pressure; - vaporization of material by converting it into plasma; - vaporization of material by heating it in vacuum electron-beam units; - vaporization of material by laser-induced heating; - vaporization of material by electrical conductor (fine wire) burst in an inert atmosphere; - mechanical methods of grinding to sub-micron size. The technologies listed above have the following disadvantages: 1) they could hardly be used for production of nanopowders in industrial scale (starting from 1 ton per month); 2) the technologies mentioned are rather specific in the sense that they could hardly be applied for production of nanopowders of a wide range of materials; 3) some technologies are toxic for the environment; 4) the use of the technologies listed above requires complicated preconditioning of raw materials before the production. The proposed technology does not have these disadvantages. The patented method of nanopowders production consists in vaporization of source material by means of a special industrial electron accelerator. The vaporization is followed by high-temperature steam cooling and condensation of material. Finally, fine-grained powder of any compound is produced.