NOVELTY - The hydrogen generating device comprises a first cylindrical element (1) within which a reactive mixture flows, a second element (2) forming an electrode tip (6) arranged along the axis of the first element, and a continuous current generator to establish a potential difference between the elements. The first cylindrical element comprises a conductive area to define with the second element, an area to establish an electrical discharge, a cylindrical electrode (4), and a first cylindrical insulating sleeve (3) closed at the side of the second element.    USE - The device is useful for generating hydrogen by fuel reforming assisted by an electric discharge generating a plasma, and for stationary applications related to aerospace and automotive fields e.g. in a fuel cell of a motor vehicle.    ADVANTAGE - The hydrogen generating device is capable of easily generating the hydrogen and safely storing the generated hydrogen using fuel reforming installations at low cost without using any precious metals, and provides enhanced effectiveness throughout the duration of the vehicle driving.    DETAILED DESCRIPTION - The hydrogen generating device comprises a first cylindrical element (1) within which a reactive mixture flows, a second element (2) forming an electrode tip (6) arranged along the axis of the first element, and a continuous current generator to establish a potential difference between the elements. The first cylindrical element comprises a conductive area to define with the second element, an area to establish an electrical discharge, a cylindrical electrode (4), and a first cylindrical insulating sleeve (3) closed at the side of the second element. A unit for continuously vary the distance between the first conductive area of the first cylindrical element and the second element to vary the length of electric discharge along a flow of the reaction mixture and/or the fuel nature. The cylindrical electrode is mounted within the first insulating sleeve. The cylindrical electrode of the first cylindrical element is rotating along the axis of the first cylindrical element. A second insulating cylindrical sleeve is applied on the inner surface of the cylindrical electrode. The cylindrical electrode is motionless, and the second insulating sleeve is rotating along the axis of the first cylindrical element. A conductive area is delimited by an electrical insulation element. The electrode is stationary, and the second element forming an electrode tip is rotating along its axis. The cylindrical electrode comprises an alternating conductive element and electrically insulating elements along its axis defining a succession of coaxial conducting rings separated from one another. A switching device is able to select the active conducting part, and the other conductive parts are electrically insulated. The movable cylindrical electrode of the first cylindrical element comprises a slit provided for injection of reactive mixture. The slit cut in the cylindrical electrode of the first cylindrical element having a size equal to the flow of cylindrical electrode. The first insulating sleeve comprises a hole provided for the injection of reactive mixture and arranged opposite to the slit. The slits are each cut into the cylindrical electrode against each holes provided in the sleeve. The length of the slits has a size less than the flow of the cylindrical electrode. The holes of the first sleeve are diametrically opposite with respect to the other with respect to the axis of the first cylindrical element. The second element comprises a helical groove, dug in the element such as in insulation. Earth is coupled to the conductive area of the first cylindrical element, or to the pointed electrode of the second element. An INDEPENDENT CLAIM is included for a process for generating hydrogen by fuel reforming.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of a hydrogen generating device (Drawing includes non-English language text).    First cylindrical element (1)    Second element (2)    First cylindrical insulating sleeve (3)    Cylindrical electrode (4)    Electrode tip. (6)