A vehicle is provided with an engine, an H2 and CO tank, a CO2 reclaimer, an electrolytic solution tank, an electrolyzer, a water tank and the like. During operation of the engine, an exhaust gas is introduced into an absorbing liquid in the CO2 reclaimer so as to recover CO2 in the exhaust gas and to store the same in the electrolytic solution tank. While supplying the absorbing liquid having absorbed CO2 and water to the electrolyzer from the electrolytic solution tank and the water tank, respectively, electric power is supplied to the electrolyzer. As a result, a mixed gas composed of CO and H2 from CO2 and water. The generated mixed gas is temporarily stored in the H2 and CO tank and is supplied to the engine.