NOVELTY - A high-pressure hydrogen production apparatus comprises a barrier member pressed in a direction of a single cell (7) by a high-pressure hydrogen gas separated in a second compartment (16) by gas-liquid separation of the high-pressure hydrogen gas and water guided together through a hydrogen gas guide channel, while the water separated from the high-pressure hydrogen gas is supplied to a fluid channel (8) of a cathode side separator (5) through the hydrogen gas guide channel.    USE - For producing high-pressure hydrogen.    ADVANTAGE - Hydrogen gas generated on a cathode side of a solid polymer electrolyte membrane is prevented from leaking toward an anode side via the solid polymer electrolyte membrane. An excellent electrolytic efficiency can be obtained.    DETAILED DESCRIPTION - A high-pressure hydrogen production apparatus comprises:    (1) a high-pressure vessel (14) comprising a first compartment (15) for housing a single cell and a second compartment communicating with the first compartment on a cathode side of the single cell;    (2) a barrier member provided at an interface between the first compartment and the second compartment for water-tightly separating the compartments, and provided retractably in the direction of the single cell along an inner wall of the second compartment; and    (3) a hydrogen gas guide channel provided within the high-pressure vessel for guiding the high-pressure hydrogen gas accompanied by water obtained in a fluid channel of a cathode side separator into the second compartment.    The barrier member is pressed in the direction of the single cell by the high-pressure hydrogen gas separated in the second compartment by gas-liquid separation of the high-pressure hydrogen gas and water guided together through the hydrogen gas guide channel, while the water separated from the high-pressure hydrogen gas is supplied to the fluid channel of the cathode side separator through the hydrogen gas guide channel.    DESCRIPTION OF DRAWING(S) - The figure is an illustrative sectional view showing a high-pressure hydrogen production apparatus.    Cathode side separator (5)    Single cell (7)    Fluid channel (8)    High-pressure vessel (14)    First compartment (15)    Second compartment (16)