A reactor for electroplating a workpiece includes a vessel having a ring contact arranged to support a workpiece in a horizontal orientation. In an embodiment of the invention, an electrode is arranged below the ring contact, and a pressing member is arranged above the ring contact to press a workpiece into electrical engagement with the ring contact. The vessel may be adapted to contain an electroplating fluid between a top of the ring contact and the electrode. In one embodiment, a movable intermediate workpiece support assembly is carried by the vessel, the support assembly being actuatable to lower a workpiece carried thereby to deliver the workpiece to be supported accurately and precisely on the ring contact.