PURPOSE: To efficiently produce fine reduced metal powder having high purity and extremely small particle size by introducing a metal compd. soln. and hydrocarbon having an oxygen atom in the molecule into high-temp. combustion gas flow and executing reduction and thermal decomposition in the state of the specific value or above of gaseous H2 and CO.

CONSTITUTION: The soln. or dispersion of the metal compd. is introduced simultaneously with or separately from the hydrocarbon having the oxygen atom in the molecule into the high temp. combustion gas flow formed by causing the complete combustion of a natural gas, etc., to effect the reduction and thermal decomposition in the state of respectively ≥8% H2 and CO gaseous compsns. The chloride, nitrate, etc., of iron, cobalt and nickel selected from transition metals are used as the metal compd. and alcohols such as ethanol and propanol are used as the hydrocarbon. The metal compd. introduced into the gaseous flow is stagnated for at least about 50ms in the furnace. The fine metal powder having the high purity and uniform granular shapes is effectively obtd. in this way.