ELECTROCHEMICAL HYDROGEN PUMP

An electrochemical hydrogen pump includes an electrolyte membrane, an anode catalyst layer in contact with one primary surface of the electrolyte membrane, a cathode catalyst layer in contact with the other primary surface of the electrolyte membrane, an anode gas diffusion layer in contact with the anode catalyst layer, a cathode gas diffusion layer in contact with the cathode catalyst layer, and a voltage applicator that applies a voltage between the anode catalyst layer and the cathode catalyst layer. Application of the voltage by the voltage applicator causes hydrogen in a hydrogen-containing gas supplied to above the anode catalyst layer to move above the cathode catalyst layer and to be pressurized. The anode gas diffusion layer includes a porous carbon sheet that has a smaller porosity in a first surface layer, which is on the anode catalyst layer side, than in the inside layer deeper than the first surface layer.