NOVELTY - The hydrogen generation device (100) comprises a housing (101) including hydrogen outlets, a cell module including removable elementary cells (110) with electrolytes between electrodes, a wiring, which electrically parallely switches the electrodes of the elementary cells, a switch (124), which is formed at the wiring to open and close a circuit between a positive electrode and a negative electrode of each elementary cell, a temporary storage space (104) in the hydrogen outlet for storing the hydrogen, which is produced in the elementary cells, and a hydrogen-permeable membrane.    USE - Device for generating hydrogen useful in vehicles (claimed) such as passenger cars including sport utility vehicles, buses, trucks, various utility vehicles, water vehicles including variety of boats and ships and aircraft, hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-driven vehicles and other vehicles with alternative fuel (such as fuel that is obtained from other sources than petroleum), and useful as a fuel source for a fuel cell system, which is useful to supply small electrical/electronic devices or portable devices with energy and is useful as a power supply for industrial use at home and for operating the vehicles.    ADVANTAGE - The hydrogen generation device can be simply and economically produced and installed, is capable of safely and easily generating the hydrogen with high volumes and high performance in an economical manner, and is capable of efficiently producing environmental-friendly byproduct thus safely and simply utilizing the byproduct as fuel source in the vehicles.    DETAILED DESCRIPTION - The hydrogen generation device (100) comprises a housing (101) including hydrogen outlets, a cell module including removable elementary cells (110) with electrolytes between electrodes, a wiring, which electrically parallely switches the electrodes of the elementary cells, a switch (124), which is formed at the wiring to open and close a circuit between a positive electrode and a negative electrode of each elementary cell, a temporary storage space (104) in the hydrogen outlet for storing the hydrogen, which is produced in the elementary cells, a hydrogen-permeable membrane, which is arranged in a side of the cell module and selectively lets through only hydrogen to the outlet, and a water supply unit, which delivers water for hydrolysis in each elementary cell, which is filled with the electrolytes. The electrolytes have a chemical hydride such as magnesium hydride and a catalyst such as magnesium chloride. The hydrogen is produced as water source in each individual elementary cell by hydrolysis of the chemical hydride with the electrolyte if the switch is closed, and the produced hydrogen is delivered by the outlets. The water supply unit has a tank storing water, which is to be delivered at each elementary cell in the housing, a water supply tube connected to the water storage tank for delivering the water from outside of the housing, and a water-permeable membrane disposed to a water supply level to arrange between the water storage tank and the cell module. The water supply tube connects the water storage tank with a fuel cell stack to deliver water from the fuel cell stack to the water storage tank. A stop valve is installed in the water supply tube to prevent a return flow of the water. The housing has a base housing and a cover housing, which is to be opened and simply removes a byproduct. The base housing and the cover housing are formed as a screwed connection. The device further comprises a water storage tank, which is connected at the hydrogen outlet of the housing and stores and receives the hydrogen produced in each elementary cell by the hydrogen outlet, where the stored water delivers by an additional outlet. The stop valve is arranged in a tube between the housing and the water storage tank.    DESCRIPTION OF DRAWING(S) - The diagram shows a cross-sectional view of a hydrogen generation device.    Hydrogen generation device (100)    Housing (101)    Temporary storage space (104)    Elementary cells (110)    Switch. (124)