Fine powder of a metal is made by vaporizing the metal in a vaporization chamber, mixing the metallic vapor with an inert carrier gas, and then adiabatically expanding the mixture through a nozzle, which preferably is a convergent-divergent nozzle. A jet flow from the nozzle is very rapidly cooled by this adiabatic expansion, which quickly condenses the metal vapor in the jet flow into very fine particles. Optionally the jet flow is directed against a metal powder collecting means, which may be a collection plate, but preferably is a bath of oil which entrains the particles and keeps them from agglomerating together by partially neutralizing their surface activity. Thus fine metal powder with particle diameters of the order of a few hundreds of angstroms can be economically produced.