Method for electrochemical measurement of hydrogen permeation though a metallic or metallised workpiece using a double cell which comprises a loading cell and a measuring cell which are electrically isolated from one another, and wherein the measuring cell has an electrolyte and an oxygen electrode, wherein the oxygen electrode is a gas diffusion electrode having a gas-permeable, electrolyte-impermeable membrane, and wherein the method comprises the following steps: (a) introducing the workpiece between the loading cell and the measuring cell, so that a first surface of the workpiece is in contact with the loading cell and the opposite second surface of the workpiece is in contact with the measuring cell; (b) carrying out a loading reaction in the loading cell in order to load the first surface of the workpiece with hydrogen, wherein the loading of the workpiece with hydrogen is effected though a hydrogen-forming reaction which is made possible through an interaction of an electrolyte with the workpiece surface, selected from a pickling reaction, a passivation reaction, a chemical or electrochemical deposition reaction, a decoating process, an etching reaction, electropolishing, a degreasing process and a simulated corrosion process; (c) enabling a redox reaction in the measuring cell without applying an external current or voltage source, wherein the second surface of the workpiece functions as an anode at which the hydrogen formed in (b) and diffused through the workpiece is oxidised, and the oxygen electrode functions as a cathode at which oxygen is reduced, wherein a flow of electrons takes place via an electrical conductor between the anode and cathode and a flow of ions takes place via the electrolyte; (d) measuring the electron flow in the electrical conductor and determining the charge that has flowed; (e) determining the amount of diffused hydrogen on the basis of the charge that has flowed. (a) introducing the workpiece between the loading cell and the measuring cell, so that a first surface of the workpiece is in contact with the loading cell and the opposite second surface of the workpiece is in contact with the measuring cell; (b) carrying out a loading reaction in the loading cell in order to load the first surface of the workpiece with hydrogen, wherein the loading of the workpiece with hydrogen is effected though a hydrogen-forming reaction which is made possible through an interaction of an electrolyte with the workpiece surface, selected from a pickling reaction, a passivation reaction, a chemical or electrochemical deposition reaction, a decoating process, an etching reaction, electropolishing, a degreasing process and a simulated corrosion process; (c) enabling a redox reaction in the measuring cell without applying an external current or voltage source, wherein the second surface of the workpiece functions as an anode at which the hydrogen formed in (b) and diffused through the workpiece is oxidised, and the oxygen electrode functions as a cathode at which oxygen is reduced, wherein a flow of electrons takes place via an electrical conductor between the anode and cathode and a flow of ions takes place via the electrolyte; (d) measuring the electron flow in the electrical conductor and determining the charge that has flowed; (e) determining the amount of diffused hydrogen on the basis of the charge that has flowed. <EOS>