NOVELTY - The hydrogen production installation comprises a purified water supply circuit (1), a flow in a cell for water electrolysis through a first chamber for regulating water level and separating water, a control unit, and a cooling/heating circuit in which coolant circulates. The water electrolysis cell comprises a unit for electrolysis of water, direct current generator (5), an outlet for oxygen and water mixture connected to the first chamber, and an outlet for hydrogen and water mixture connected to a second chamber for controlling the level and separating water and hydrogen.    USE - The installation is useful for producing hydrogen gas by water electrolysis, where the hydrogen is useful for storage in a metal hydride or for the consumption in a fuel cell.    ADVANTAGE - The installation ensures easy, safe, energy efficient and large scale production of hydrogen gas with high purity by effective water electrolysis, and has high resistance to strong differential pressure, high chemical and electrochemical stability, long lifetime and high ability to operate at low or high pressure.    DETAILED DESCRIPTION - The hydrogen production installation comprises a purified water supply circuit (1), a flow in a cell for water electrolysis through a first chamber for regulating water level and separating water, a control unit, and a cooling/heating circuit in which coolant circulates. The water electrolysis cell comprises a unit for electrolysis of water, direct current generator (5), an outlet for oxygen and water mixture connected to the first chamber, an outlet for hydrogen and water mixture connected to a second chamber for controlling the level and separating water and hydrogen, an inlet connected to an outlet of the first chamber through a first circulation unit, an inlet connected to an outlet of the second chamber through a second circulation unit, and a temperature sensor connected to the oxygen and water output or present on the hydrogen and water outlet. The first chamber is connected to a circuit for extraction of oxygen. The second chamber is connected to a circuit for extraction of hydrogen. The water electrolysis unit comprises a proton exchange membrane. The first and second chambers are connected to each other by a pipe controlled by a first solenoid valve. A purified water feeding circuit is connected on the running water network, and comprises a pressure regulator, a water purification unit, a storage reservoir for purified water, a third circulation unit and a second solenoid valve in series. The second solenoid valve and the third circulation unit are operated to feed the first oxygen and water separation chamber in water when the water level in the chamber reaches a minimum level. The oxygen extraction circuit comprises an oxygen purification unit carrying out a water extraction, where the extracted water is reinjected in the purified water storage reservoir by a pipe and by the circulation unit, a unit for gas analysis, a unit for regulating the pressure of oxygen. The first separation chamber is further connected to a first unit for gas evacuation for lowering the pressure by releasing oxygen in case of high pressure in the oxygen extraction circuit. The hydrogen extraction circuit comprises a purification unit of hydrogen performing a water extraction, where the extracted water is reinjected in the purified water storage reservoir by a pipe and by the circulation unit, a unit for gas analysis, and a unit for regulating the hydrogen pressure. The second separation chamber is further connected to a second unit for gas evacuation for lowering the pressure by releasing hydrogen in the case of high pressure in the hydrogen extraction circuit. The control unit comprises a programmable logic controller of which the inlets are connected to: first and second chambers for level control; a level sensor of the pure water storage reservoir; the pressure regulators; the water electrolysis unit; the conductivity sensor; a flow sensor mounted on the inlet of the water electrolysis unit; the gas analysis units; the hydrogen pressure sensor; the gas purification unit; the current generator; and to a temperature sensor. The outlets of the control unit are connected to: the first, second and third circulation units; to solenoid valves; the direct current generator; the pressure regulators; and the purification units. A display and capture unit is connected to the programmable logic controller.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a hydrogen production installation (Drawing includes non-English language text).    Purified water supply circuit (1)    Regulated pressure (2)    Purification unit (3)    Oxygen and hydrogen production (4)    Direct current generator. (5)