Abstract: A process and apparatus for electrolytically depositing a uniform metal layer onto a workpiece is provided. The workpiece, for example a circuit board, serves as a cathode. The anode is insoluble and dimensionally stable. Both anode and cathode are immersed in a plating solution contained in an electrolytic container. The solution includes (a) ions of the metal to be deposited on the workpiece, (b) an additive substance for controlling physical-mechanical properties of the metal to be deposited, such as brightness, and (c) an electro-chemically reversible redox couple forming oxidizing compounds when contacting the anode. A metal-ion generator is provided, supplying metal parts of the metal to be deposited onto the workpiece; The plating solution is circulated between the container and the ion generator for maintaining a reaction between the oxidizing compounds and the metal parts for forming metal ions.