NOVELTY - A fuel reformer (100) comprises reformer burner (110) having internal space where combustion fuel flows to discharge combustion fuel in internal space from burner outlet to form flame (140), reforming pipe disposed to surround flame portion, where the pipe is filled with reforming catalyst and contains corrugated portions on surface facing burner outlet and bottom surface of pipe disposed adjacent to flame respectively, flame blocking member (150), combustion fuel supplier to supply combustion fuel to internal space, and reforming gas supplier to supply reforming gas to the pipe.    USE - As a fuel reformer (claimed) in fuel processor and fuel cell system.    ADVANTAGE - The fuel reformer improves durability and operating reliability of fuel cell system; suppresses the thermal stress at high temperatures; and prevents a burner flame from directly touching a surface of a fuel reformer by surrounding the burner flame and isolates the corrugated reforming pipe from the burner.    DETAILED DESCRIPTION - A fuel reformer comprises reformer burner containing internal space into which combustion fuel flows to discharge the combustion fuel in the internal space from an outlet of the reformer burner to form a flame, reforming pipe disposed to surround at least a portion of the flame of the reformer burner, where the reforming pipe is filled with a reforming catalyst and contains corrugated portions on a surface facing the outlet of the reformer burner and a bottom surface of the reforming pipe disposed adjacent to the flame respectively, flame blocking member disposed between the flame of the reformer burner and the reforming pipe to isolate the flame of the reformer burner from the reforming pipe, combustion fuel supplier to supply the combustion fuel to the internal space of the reformer burner, and reforming gas supplier to supply reforming gas to the reforming pipe.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a fuel reformer.    Fuel reformer (100)    Reformer burner (110)    Flame (140)    Flame blocking member (150)