NOVELTY - Heat carrier circuit (50) is provided to recover the exhaust heat which occurs as a fuel hydrogen (H2) contained in the reformed gas. The reforming group reforms the original fuel of hydrocarbon group.    USE - Fuel cell system.    ADVANTAGE - Reaction heat released in reforming type is recovered by heat carrier circuit. The exhaust heat is utilized for heating water used in water gas shift reaction. Electric power generated by fuel cell is efficient. The rate of waste heat recovery is improved. Failure of fuel cell by freezing during winter is prevented by providing antifreezing type battery heat carrier circuit. Reducing the size of storage tank and raising temperature of heat carrier, improves the versatility. The circuit is simplified as separate heat carriers are provided. The endothermic ability of system is increased and recovered quantity of condensed water is increased.    DETAILED DESCRIPTION - A fuel reformer (6) is provided for forming reformed gas containing hydrogen and carbon monoxide by oxidation reaction from original fuel of hydrocarbon group. The residual carbon monoxide formed by water gas shift reaction in reformed gas is exhausted out of carbon monoxide (CO) transformer (7). The selective oxidation reactors are provided so that at least one recovers exhaust heat before entering into fuel cell (1). A heat exchanger (31) is provided to make an heat carrier circuit recover exhaust heat of reformed gas before entering CO transformer from fuel reformer so that the temperature of reformed gas in fuel cell inlet and carbon monoxide transformer inlet is with in predetermined limits. Heat exchanger (32) makes the circuit (50) to recover exhaust heat of gas before entering the fuel cell so that reaction heat of CO selective oxidative reaction in the reaction heat and water gas shift reaction in CO transformer is recovered. The heat carrier circuit serially connecting fuel cell and reforming type has temperature of about at most 75degreesC. The heat carrier of battery heat carrier circuit which is formed on closed circuit recovers exhaust heat of fuel cell is antifreeze. An off gas burner burns waste gas of fuel cell so that a waste heat is recovered. A flow controller is provided to control the rate of flow of heat carrier based on speed of DC motor of the pump. The drive electric power is supplied from generated output of fuel cell. An INDEPENDENT CLAIM is also included for fuel cell cogeneration system which has hot water storage tank. Water of tank flows in the lower portion of heat carrier circuit.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic structure of fuel cell system. (Drawing includes non-English language text).    Fuel cell (1)    Fuel reformer (6)    CO transformer (7)    Heat exchangers (31,32)    Heat carrier circuit (50)