A fuel reforming apparatus is provided for generating a hydrogen-rich gas. The fuel reforming apparatus includes an evaporator comprising an evaporation chamber for evaporating the fuel vapor by evaporating a hydrocarbon fuel-water mixture by an evaporator using a combustion gas formed in a combustor; a heating chamber for heating the fuel vapor by a combustion gas output from the evaporation chamber; and a guiding path for guiding the combustion gas output from the evaporation chamber to the heating chamber along the floor of the evaporating room. In the heating chamber, the fuel vapor generated in the evaporation chamber is uniformly heated in an atmosphere with a homogeneous temperature of the combustion gas output from a heating medium tube, while the fuel vapor is circulating in the vapor tube.