An electrode (10) is provided for electrochemical reduction of a workpiece (20) that is to be treated. The electrode (10) has a predefined contour and contains an electrically conductive material. The electrically conductive material of the predefined contour forms an electrode core (12). The outside of the electrode core (12) is covered with an insulation layer (13). The insulation layer (13) is porous and is made of an electrically non-conductive material.