Method and regeneration apparatus for regenerating a plating composition

To achieve fast electroless plating while ensuring that the plating composition used for this purpose is stable against decomposition, a method for regenerating said plating composition is provided. Said plating composition is suitable for depositing at least one first metal on a substrate 10 and which is accommodated by at least one plating device 100. Said plating composition contains said at least one first metal in an ionic form and at least one second metal in an ionic form. Said at least one second metal may be provided in a higher and in a lower oxidation state and, when it is provided in a lower oxidation state, is capable of reducing said at least one first metal being in the ionic form to a metallic state. Said method comprises the following method steps: (a) providing a regeneration device 200 having a working electrode 205 and a counter electrode 206, said working electrode 205 being disposed in a working electrode compartment 202 and said counter electrode 206 being disposed in a counter electrode compartment 203; said working electrode compartment 202 and said counter electrode compartment 203 are separated from each other by an ion selective membrane 204; said counter electrode compartment 203 accommodates a counter electrode liquid; (b) removing at least part of said plating composition from said at least one plating device 100; (c) contacting at least a fraction of said removed plating composition with said working electrode 205 of said regeneration device 200 and polarizing said working electrode 205 cathodically, so that said at least one second metal being provided in the higher oxidation state is reduced to the lower oxidation state and said at least one first metal is deposited on the working electrode 205 in the metallic state, thereby yielding a first portion of said removed composition; thereafter (d) removing said first portion from said removed composition and then contacting a remainder of said removed composition with said working electrode 205 having said at least one first metal having been deposited thereon in method step (c) in the metallic state and polarizing said working electrode 205 anodically, so that said at least one first metal being deposited on said working electrode 205 in the metallic state is dissolved into said remainder of said removed composition to form said at least one first metal in the ionic form, thereby yielding a second portion of said removed composition; thereafter (e) returning said first and sec