In a device, rod-shaped objects 10 (rods of various length and diameter) are electrochemically partially processed in dip plants (galvanized, pickled). Stationary tubular electrodes 30, into which the rods 10 are centrically entered, are provided in the plating tank of the plant. The surfaces to be plated are each axially limited by an adjustable membrane carrier 26, in which elastic shielding membranes 9 for delimiting the field lines are arranged. The membranes 9 are held by membrane holders 5. The membrane holders 5 are arranged in a cage where they are free to move radially and are provided with inner centering springs 7 and with outer centering springs 19 so that the membrane holder 5 and the membranes 9 are held in such a way as to be self-centering.