NOVELTY - Fuel-cell electric vehicle (V) comprises fuel cell (FC), vehicle idling detection unit, operation stopping prediction unit, and residual water amount control unit (50). The fuel cell generates electricity with a reactant gas supplied to it. The vehicle idling detection unit determines whether the vehicle is running at idle. The operation stopping prediction unit predicts forthcoming stopping of operation of the vehicle running at idle.    USE - As a fuel cell electric vehicle.    ADVANTAGE - The vehicle reduces energy consumption and/or noise in the scavenging process. The vehicle allows reduction of residual water inside the fuel cell before the operation of the vehicle is actually stopped thus shortens a scavenging time. The vehicle allows increased removal of residual water from inside of fuel cell.    DETAILED DESCRIPTION - Fuel-cell electric vehicle comprises fuel cell, vehicle idling detection unit, operation stopping prediction unit, and residual water amount control unit. The fuel cell generates electricity with a reactant gas supplied to it. The vehicle idling detection unit determines whether the vehicle is running at idle. The operation stopping prediction unit predicts forthcoming stopping of operation of the vehicle running at idle. The residual water amount control unit reduces residual water inside the fuel cell in response to a prediction of the forthcoming stopping of the operation of the vehicle made by the operation stopping prediction unit. The fuel-cell electric vehicle includes humidifier, cooling system, flow rate regulating unit, and pressure regulating unit. The residual water amount control unit comprises unit for causing part of the reactant gas to be detoured around the humidifier in response to the prediction of the forthcoming stopping of the operation of the vehicle made by the operation stopping prediction unit to lower a humidity of the reactant gas. Regulating a pressure of the reactant gas supplied to the fuel cell, is configured to reduce the pressure of the reactant gas in response to the prediction of the stopping of the operation of the vehicle made by the operation stopping prediction unit. An INDEPENDENT CLAIM is included for a method of reducing residual water in a fuel cell before scavenging the residual water.    DESCRIPTION OF DRAWING(S) - The figure shows schematic diagram of fuel cell electric vehicle.    Electrolyte membrane (1)    Anode (2)    Cathode (3)    Separators (4, 5)    Air compressor (22)    Residual water amount control unit (50)    Fuel cell (FC)    Fuel-cell electric vehicle (V)