PURPOSE: To lessen fluctuation of pressure of discharged reformed gas without using any particular means by reforming gasified feed gas to H2-rich gas by causing catalytic reaction between an evaporator provided with a packed bed of hot particles and the gasified feed gas.

CONSTITUTION: Combustion gas burnt by a burner 7 flows downward through a combustion chamber 8a in the direction of a chainlined arrow mark G and exchanges heat with hot particles 19 and evaporator 9, changes the direction of the flow and enters an external peripheral chamber of an inside separating wall 16 from the bottom end of the combustion chamber exchanging heat with a reforming device 10 during flowing upward. The waste gas is discharged through a manifold 15 to the outside of the system from a waste gas pipe 21. On one hand, liquid fuel is introduced to the evaporator 9 through a liquid fuel feed pipe 14 in the direction shown by an arrow mark F, where the fuel is gasified, then introduced into the reforming device 10 through the manifold 15. The gasified fuel gas is reformed to H2-rich reformed gas in the reforming device 10 by the reforming reaction caused by the contact of the gas with catalyst 17 at high temp. the gas is fed to a main body of a fuel cell from a manifold 24 through a feed pipe 19 of the reformed gas.