NOVELTY - An electric power supply apparatus (400) is provided with a gas producer (300), fuel cell (410) and electric power supply device (440) which supplies electric power to electric load. The gas producer generates oxygen and hydrogen, and the fuel cell generates direct current electric power using hydrogen gas generated by gas producer. The direct current electric power generated in fuel cell is passed to electric power supply device which supplies the electric power to electric load. The gas producer includes electrolyte solution, anode electrode and cathode electrode.    USE - Electric power supply apparatus is used in solar energy power generation apparatus and used for supplying electric power in home.    ADVANTAGE - In electric power supply apparatus, the hydrogen gas is easily supplied to the fuel cell, and thus efficiently generates electric power.    DETAILED DESCRIPTION - An electric power supply apparatus is provided with a gas producer, fuel cell and electric power supply device which supplies electric power to electric load. The gas producer generates oxygen gas and hydrogen gas, and the fuel cell generates direct current electric power using at least hydrogen gas generated by gas producer. The direct current electric power generated in fuel cell is passed to electric power supply device which supplies the electric power to electric load. The gas producer includes electrolyte solution, anode electrode having group III nitride crystal and cathode electrode immersed in the electrolyte solution, and current source which passes direct current between the anode and cathode electrode. The group III nitride crystal includes gallium nitride crystal, and the cathode electrode includes platinum. The electrolyte solution is hydrochloric acid.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic structural view of electric power supply apparatus. (Drawing includes non-English language text)    Gas producer (300)    Electric power supply apparatus (400)    Fuel cell (410)    Gas supply line (420,430)    Electric power supply device (440)