NOVELTY - The fuel cell system comprises a control valve, a first warm water generating unit (120), and a second warm water generating unit (140), a unit (150) for storing first or second warm water, and a high temperature reformer (130). The warm water storage unit is connected to the first warm water generating unit. The reformer delivers the heat generated in a fuel cell stack in the supplied constant from the fuel cell stack and produces electricity using hydrogen supplied from the reformer. The reformer delivers heat, generated in a burner part (131) of the reformer, to the first warm water.    USE - Used as a fuel cell system.    ADVANTAGE - The fuel cell system exhibits good warm water producing function, and minimizes the reforming efficiency degradation at the reformer.    DETAILED DESCRIPTION - The fuel cell system comprises a control valve, a first warm water generating unit (120), a second warm water generating unit (140), a unit (150) for storing first or second warm water, and a high temperature reformer (130). The warm water storage unit is connected to the first warm water generating unit. The reformer delivers the heat generated in a fuel cell stack in the supplied constant from the fuel cell stack and produces electricity using hydrogen supplied from the reformer. The reformer delivers heat, generated in a burner part (131) of the reformer, to the first warm water. The first warm water generating unit controls the first warm water provided to the warm water storage unit. The control valve is connected to the first warm water generating unit, and comprises a first valve connected to the first and second warm water generating units and a second valve connected to the warm water storage unit. The first warm water stored in the warm water storage unit has a temperature of 60-70 degrees C and the second warm water stored in the warm water storage unit has a temperature of 80-90 degrees C. The warm water storage unit comprises a first warm water storage and a second warm water storage unit. The first warm water storage unit is connected to a heating apparatus. The second warm water storage unit is connected to an absorption air conditioner. The control valve is equipped between the warm water storage unit and the heating apparatus or the absorption air conditioner. The second warm water is provided to the absorption air conditioner. The first warm water is provided to the heating apparatus. The reformer includes a carbon monoxide (CO) shifter and a CO removing unit.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a fuel cell system (Drawing includes non-English language text).    First warm water generating unit (120)    Reformer (130)    Burner part (131)    Second warm water generating unit (140)    Warm water storage unit. (150)