NOVELTY - A hydrogen charging apparatus comprises: a hydrogen generation unit (110) to generate hydrogen; a hydrogen charging unit (120) to charge the generated hydrogen to a hydrogen storage medium (210); and a cooling unit (130) that cools hydrogen storage medium.    USE - As a hydrogen charging apparatus (claimed); for generating hydrogen for fuel in an electricity generation reaction in a fuel cell (including fuel cell for mobile devices), and for storing hydrogen in a storage medium.    ADVANTAGE - The hydrogen charging apparatus includes hydrogen storage medium that can readily store and discharge hydrogen. The cooling unit cools the charging cradle during hydrogen charging, and cools solid hydrogen storage medium of hydrogen storage cartridge mounted to charging cradle; which in turn provides improved hydrogen charging and discharging characteristics of the solid hydrogen storage medium i.e. high charging pressure and low discharging pressure. As the temperature for hydrogen charging is reduced when hydrogen is charged in solid hydrogen storage medium, pressure of hydrogen charging characteristics is reduced. This denotes that hydrogen charging is achieved satisfactorily in solid hydrogen storage medium compared to case when temperature is high although pressure of hydrogen supplied from hydrogen generation unit is low. Thus, hydrogen charging can be satisfactorily achieved without need for an installation of additional booster. Further, when solid hydrogen storage medium, in which hydrogen is charged, is used for operation of electronic apparatus, since the temperature is raised to room temperature, the characteristics of the solid hydrogen storage medium return to original characteristic. Thus, pressure of hydrogen when hydrogen is discharged is raised higher than cooled state, and thus, hydrogen supply to anode is achieved smoothly i.e. ideal hydrogen charging and discharging characteristic are achieved. Thus, both charging and discharging hydrogen are easily and smoothly performed. To rapidly charge hydrogen within 10 minutes, charging pressure of hydrogen is increased twice or more than a normal charging pressure. In this way, hydrogen is rapidly cooled, charging pressure of hydrogen is reduced to half of the normal charging pressure or less, and thus, the hydrogen charging and discharging characteristic is advantageous for realizing a rapid charging function. Also, as reaction in which hydrogen reacts with the solid hydrogen storage medium during charging is an exothermic reaction; when solid hydrogen storage medium is cooled, charging efficiency is also increased.    DETAILED DESCRIPTION - A hydrogen charging apparatus comprises: a hydrogen generation unit (110) to generate hydrogen; a hydrogen charging unit (120) to charge the generated hydrogen to a hydrogen storage medium (210); and a cooling unit (130) that cools hydrogen storage medium. The hydrogen storage medium is solid hydrogen storage medium. The cooling unit is installed in hydrogen charging unit; and cools hydrogen storage medium with thermoelectric refrigerator, thermo-acoustic refrigerator, or phase change of a coolant. The cooling unit cools hydrogen storage medium to -20 to 30 degrees C. The hydrogen generation unit generates hydrogen by electrolysis reaction, or catalyst reaction. The hydrogen generation unit that uses electrolysis reaction comprises water tank to store water, gas-liquid separation tank having hydrogen-producing unit disposed in it to generate hydrogen from water supplied from water tank, and dehumidifier to remove water from the generated hydrogen; electrolyzing unit that uses alkali aqueous solution electrolyte; electrolyzing unit that uses ion conductive membrane as electrolyte; or electrolyzing unit that uses oxidation and reduction reaction of optical catalyst by radiating light to optical catalyst and generates hydrogen by reacting catalyst selected from alkali metal or borohydride (MxBHy) (where x and y are not defined) with water. The pressure of hydrogen that is supplied to hydrogen charging unit from hydrogen generation unit is 0.01-10 atm. The hydrogen charging unit charges hydrogen storage medium with hydrogen at first pressure, and the hydrogen storage medium discharges hydrogen at second pressure, where first pressure is less than second pressure. INDEPENDENT CLAIMS are included for the following:    (1) a hydrogen charging unit comprising: a hydrogen storage cartridge (200); a hydrogen storage medium disposed in hydrogen storage cartridge; a charging cradle (121) to which hydrogen storage cartridge is attachable to charge hydrogen storage medium with hydrogen, in which the cradle is attachable to a hydrogen source which provides the hydrogen to be charged in the hydrogen storage medium; and a cooling unit to cool hydrogen storage medium when hydrogen storage medium is charged with hydrogen; and    (2) method for charging hydrogen involving: cooling hydrogen storage medium; and charging hydrogen to the hydrogen storage medium while the hydrogen storage medium is cool.    DESCRIPTION OF DRAWING(S) - The figure shows a structure of the hydrogen charging apparatus.    Hydrogen generation unit (110)    Tank containing water for electrolysis (111)    Electrolyzing unit (113)    Hydrogen charging unit (120)    Charging cradle (121)    Cooling unit (130)    Hydrogen storage cartridge (200)    Solid hydrogen storage medium (210)