NOVELTY - A modifier (1) comprises modification catalyst (2) which modifies hydrogen-type fuel and generates hydrogen, oxidation catalyst (3) which is arranged upstream and oxidizes by oxygen environment rather than modification catalyst, outer jacket case (4) which accommodates modification catalyst and oxidation catalyst inside, inlet port (5) which takes in hydrogen-type fuel as mixed gas with air from upstream path arranged upstream rather than oxidation catalyst, and exit part which discharges generated reformed gas to downstream path arranged more downstream than the modification catalyst.    USE - A modifier for hydrogen-type fuel (claimed).    ADVANTAGE - Performance degradation of the catalyst inside is suppressed.    DETAILED DESCRIPTION - A modifier (1) comprises modification catalyst (2) which modifies hydrogen-type fuel and generates hydrogen, oxidation catalyst (3) which is arranged upstream and oxidizes by oxygen environment rather than modification catalyst, outer jacket case (4) which accommodates modification catalyst and oxidation catalyst inside, inlet port (5) which takes in hydrogen-type fuel as mixed gas with air from upstream path arranged upstream rather than oxidation catalyst, exit part which discharges generated reformed gas to downstream path arranged more downstream than the modification catalyst, outer peripheral wall part which surrounds outer periphery of modification catalyst and oxidation catalyst, and the outer jacket case, water storage part (10) which can store liquid water content which appears in inner wall of exit part of outer jacket case, and is formed in outer peripheral wall part of outer jacket case, and guide passage (11) which guides liquid water content which appeared in inner wall of exit part of outer jacket case to the water storage part, and is formed in outer peripheral wall part of outer jacket case.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the modifier.    Modifier (1)    Modification catalyst (2)    Oxidation catalyst (3)    Outer jacket case (4)    Inlet port (5)    Water storage part (10)    Guide passage (11)