To rapidly improve the energy efficiency in a fuel reformer and rapidly heat up the fuel reformer into a stationary state at the time of starting a fuel cell.
The amount of methanol fed from a methanol tank 28 to an evaporating part 90 is limited at the time of starting a fuel reformer 22. Thereby, the heat quantity which is lost in the evaporating part 90 of a combustion gas fed from a burner 34 to the evaporating part 90 is suppressed and the resultant combustion gas is converted into a high-temperature combustion waste gas and discharged into a combustion waste gas introduction part 94. A reforming part 92 is rapidly heated up by utilizing the heat quantity of the high-temperature combustion waste gas. When the fuel reformer 22 is kept in a stationary state, the temperature of the combustion gas fed from the burner 34 is controlled to sufficiently reduce the temperature of the combustion waste gas discharged to the combustion waste gas introduction part 94.