NOVELTY - The vehicle has a carbon monoxide sensor (250), which detects carbon monoxide in the air supplied to a fuel cell (200) by a compressor (202), and a sensor (206) which detects the state of charge (SOC) of a battery (207). A controller microprocessor (254) controls operation of the fuel cell based on carbon monoxide and state of charge of the battery (207), and stops operation of the fuel cell (200) at a lower carbon monoxide concentration the higher the state of charge of the battery (207).    USE - None given.    ADVANTAGE - The performance of the fuel cell of the fuel cell vehicle is prevented from falling due to toxic substances such as carbon monoxide in the intake air without reducing the running performance of the fuel cell vehicle.    DETAILED DESCRIPTION - The vehicle has a fuel cell (200), which generates power using fuel gas containing hydrogen, an air feeder (202) which supplies air to the fuel cell (200), a fuel supply device (201, 205) which supplies gas to the fuel cell (200), and a motor (208), which drives the vehicle with power generated by the fuel cell. A storage battery (207) stores power generated by the fuel cell (200) and power regenerated by the motor (208), and supplies the stored powered to the motor (207). A carbon monoxide sensor (250) detects carbon monoxide contained in the air supplied by the air feeder (202), the carbon monoxide causing the performance of the fuel cell (200) to decrease, and a sensor (206) detects the state of charge of the battery (207). The controller microprocessor (209, 254) is programmed to control operation and stop of the fuel cell (200) based on the result of detecting the carbon monoxide and the state of charge of the battery (207). The microprocessor (209, 254) is further programmed to:    (1) stop operation of the fuel cell (200) at a lower carbon monoxide concentration the higher the state of charge of the battery (207);    (2) operate the fuel cell (200) when the state of charge of the battery (207) is less than a reference value, and to stop the fuel cell (200) when the state of charge of the battery (207) is greater than a second reference value which is greater than the first reference value, regardless of the carbon monoxide detection result;    (3) operate or stop the fuel cell (200) based on the time average value of the carbon monoxide concentration, and the state of charge of the battery (207).    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of a schematic construction of the fuel cell vehicle.    Fuel cell (200)    Fuel supply device (201, 205)    Air feeder (202)    Storage battery state of charge sensor (206)    Storage battery (207)    Motor (208)    Carbon monoxide sensor (250)    Controller microprocessor (209, 254)