A fuel reformer, includes: a reformer burner, which generates a flame in a reforming pipe disposed to surround at least the flame of the reformer burner, the reforming pipe being filled with a reforming catalyst and having corrugated portions on a surface facing the reformer burner and a bottom surface of the reforming pipe disposed adjacent to the flame in which a flame blocking member is disposed between the flame of the reformer burner and the reforming pipe to isolate the flame of the reformer burner from the reforming pipe.