NOVELTY - The water electrolysis device comprises a stack of elementary electrolytic cells formed of a cathode (2), an anode (4) and an electrolyte (6) interposed between the cathode and anode, and a first device (8) forming an electrical and fluid interconnector consisting of a metal part (80) delimited by plane P1. The first metal part comprises two chambers (81, 82) superimposed to one another and holes distributed over the surface perpendicular to the plane and divided into two groups. The plane P1 of the first interconnector is in mechanical contact with a plane of the cathode.    USE - The device is useful for electrolysis of water at high temperature and in an assembly for the production of hydrogen (claimed).    ADVANTAGE - The device provides is capable of easily and economically producing the hydrogen with high efficiency by enhancing the electrolysis of water at high temperatures in real time, and provides uniform current density in each electrolysis cell and increases the rate of steam used by each electrolysis cell.    DETAILED DESCRIPTION - The water electrolysis device comprises a stack of elementary electrolytic cells formed of a cathode (2), an anode (4) and an electrolyte (6) interposed between the cathode and anode, and a first device (8) forming an electrical and fluid interconnector consisting of a metal part (80) delimited by plane P1. The first metal part comprises two chambers (81, 82) superimposed to one another and holes distributed over the surface perpendicular to the plane and divided into two groups. The plane P1 of the first interconnector is in mechanical contact with a plane of the cathode. The adjacent chamber is arranged for collecting the hydrogen produced by electrolysis, and is present away from the chamber through which steam is supplied. The holes have a circular section having a diameter of 1.25-2.5 mm, and are arranged along a parallel line with regular spacing. A distance between the center of two adjacent holes is 7-14 mm. The group of holes opened on the plane P1 and directly in the adjacent chamber is supplied with group of holes opened in the plane P1 and the extended chamber. Each hole of the group opened on the plane P1 and in the adjacent chamber is present at the center of the four holes in the group opened in the plane P1 and the extended chamber, and vice-versa. The four holes of the group form a square, where a hole of the other group is present at the center of the square. A second device forming an electrical and fluid interconnector is arranged in the device, and comprises a metal part defined by plane P2. The second metal part comprises a chamber and holes distributed over the surface perpendicular to the plane and opening in the plane P2 and the chamber. The plane P2 of the second interconnector is in mechanical contact with the plane of the anode, and a grid made of electrical conductor. The grid is in direct mechanical contact with the plane of the anode.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic sectional view of a water electrolysis device.    Cathode (2)    Anode (4)    Electrolyte (6)    First device (8)    First metal part (80)    Two chambers. (81, 82)