Method and device for providing reducing gas under constant conditions

The application relates to a method for producing metallic sponge, wherein metal-oxide-containing starting materials are reduced to metallic sponge in a reduction unit by means of a reducing gas, and reducing gas thereby consumed is drawn off from the reduction unit as top gas, and wherein the reducing gas entering the reduction unit is produced by mixing at least a partial amount of the top gas with at least one reactant gas with reduction potential to form a mixed gas, or from pure reactant gas with reduction potential. In this case, reactant gas with reduction potential is stored together with at least a partial amount of the top gas in a gas reservoir as a stored gas mixture, and at least a partial amount of the stored gas mixture is introduced into the top gas before mixing the top gas with the reactant gas with reduction potential, and/or is introduced into the reactant gas, and/or is introduced into the mixed gas.