There is provided a vehicle system, including an electromobile having a fuel cell power generator mounted therein, and a predetermined mobile unit jointable to the electromobile, such that cogeneration within the mobile unit can be realized even during the travel of the electromobile. Via a joint section 30, a vehicle 10 including a fuel cell 13 as a source of motive power is jointed to a mobile unit 20 capable of travelling and at least including a storage battery 23 and a water tank 25. The water produced in the fuel cell 13 is recovered by a water recovery section 21 via the joint section 30. The heat produced in the fuel cell 13 is recovered by a heat recovery section 22 via the joint section 30. The recovered water is warmed up with the recovered heat, and thereafter stored in the water tank 25. The hot water stored in the water tank 25 is utilized as hot water to be used for controlling the temperature of the mobile unit 20 or supplied as hot water. Any excess electric power generated by the fuel cell 13 is stored in the storage battery 23, and supplied onto electric wiring within the mobile unit 20.