NOVELTY - The apparatus (1) has a fuel gas supply apparatus (3A) for supplying gas to a fuel cell (2). A flow-meter (5), a loop-form pressure-reduction valve (6) and a diaphragm-type booster pump (8) are arranged close to an inlet-port (2a) of the fuel cell in a loop-form circular flow path (4). The flow-meter is equipped with a control part (13) that controls opening and closing of the loop-form pressure-reduction valve such that the flow-meter approximately measures goal setting flow volume of performance-evaluation conditions preset at time of electric power generation of the fuel cell.    USE - Gas flow rate control apparatus for a fuel cell evaluation test system for controlling flow volume of anode gas e.g. fuel gas such as hydrogen gas and cathode gas e.g. oxidizing agent gas such as air and oxygen, supplied to a evaluation test target object e.g. fuel cell such as polymer electrolyte fuel cell (PEFC), phosphoric acid form fuel cell (PAFC), molten carbonate fuel cell (MCFC), solid oxide fuel cell (SOFC), alkali electrolyte type fuel cell (AFC) and biofuel cell, in a fuel-cell vehicle. Can also be used in a personal digital assistant device e.g. notebook personal computer and mobile telephone, a motor vehicle, a railway and an industrial cogeneration power station.    ADVANTAGE - The flow-meter is equipped with the control part that controls the opening and closing of the loop-form pressure-reduction valve such that the flow-meter can approximately measure the goal setting flow volume of the performance-evaluation conditions preset at the time of the electric power generation of the fuel cell, so that a gas flow rate supplied to the fuel cell can be adjusted to the flow volume of the performance-evaluation conditions of the fuel cell when a user desires, thus circulating and recycling evaluation test of the fuel cell in a mounting level of the fuel-cell vehicle without exhausting unreacted hydrogen gas.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a gas flow rate control method.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of a gas flow rate control apparatus.'(Drawing includes non-English language text)'    Gas flow rate control apparatuses (1, 1A)    Fuel cell (2)    Inlet-port (2a)    Fuel gas supply apparatus (3A)    Loop-form circular flow path (4)    Flow-meter (5)    Loop-form pressure-reduction valve (6)    Diaphragm-type booster pump (8)    Control part (13)