NOVELTY - The apparatus has a purging valve which is provided for an outlet arranged adjacent to an anode of a fuel cell stack and is configured to adjust outflow of water from the fuel cell stack. A controller adjusts an opening of the purging valve based on the charge capacity obtained by integrating a current capacity of the fuel cell stack. The controller calculates the charge capacity by multiplying current capacity of fuel cell stack by scale factor, when load for output current of fuel cell stack is less than preset reference load.    USE - Apparatus for controlling hydrogen purging in fuel cell vehicle. Can also be used in motor vehicles such as passenger automobile, sports utility vehicle (SUV), bus, truck, commercial vehicle, watercraft such as boat and ship, aircraft, hybrid vehicle, electric vehicle, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicle.    ADVANTAGE - The controller calculates the charge capacity by multiplying current capacity of fuel cell stack by scale factor, when load for output current of fuel cell stack is less than preset reference load, such that the period of hydrogen purging is varied by varying current capacity. The electricity and heat are produced due to movement of electrons and vapor or water is produced through chemical reaction between hydrogen and oxygen. The impurities in the anode of the fuel cell stack are removed efficiently. The electricity generation efficiency of the fuel cell stack is improved effectively. The damage and malfunctioning of the fuel cell stack is prevented effectively. The pollution is prevented.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method for controlling hydrogen purging; and    (2) non-transitory computer readable medium storing program for controlling hydrogen purging.    DESCRIPTION OF DRAWING(S) - The drawings show the block diagram of the fuel cell system and bar graph illustrating integral value of current capacity. (Drawing includes non-English language text)    Fuel cell stack (10)    Ejector (20)    Air blower (30)    Humidifier (40)    Hydrogen supply unit (50)