Abstract: This invention relates to apparatus for electrochemical deposition onto the surface of a substrate. The apparatus includes an anode electrode 13 a support 12 for supporting the substrate 11 with its one surface 21 exposed at a location, the support and the anode electrode 13 being relatively movable to alter the gap between the anode 13 and the location to define a chamber between them and an electrical power source 18 with an ohmic contact to the seed layer 20 for creating a potential difference across the gap. The apparatus further includes a seal 14 for sealing with the seed layer 20 to define the fluid chamber 23; and the flu inlet 16 and a fluid outlet 17 to the chamber 13.