NOVELTY - The reformer comprises: a reformer main body having an internal space and selectively opening a first hole portion; a reforming catalyst filled in the first hole portion or a second hole portion; a holding fixture for first and second first reforming parts, and selectively opening and closing the first hole portion; and a handling apparatus positioned to be corresponded to the holding fixture for the first reforming part, and handling apparatus for a second reforming part positioned to be corresponded to the holding fixture for the second reforming part.    USE - The reformer is useful in a fuel cell system of a ship (claimed).    ADVANTAGE - The reformer conveniently controls the mode which selectively opens and closes the hole portion of the holding fixture, so that the holding fixture is conversion operated to the fuel reforming environment. The reformer can easily secure reforming working condition, and convert the fuel reforming mode.    DETAILED DESCRIPTION - The reformer comprises: a reformer main body having an internal space and selectively opening a first hole portion; a reforming catalyst filled in the first hole portion or a second hole portion; a holding fixture for first and second first reforming parts, and selectively opening and closing the first hole portion; and a handling apparatus positioned to be corresponded to the holding fixture for the first reforming part, and handling apparatus for a second reforming part positioned to be corresponded to the holding fixture for the second reforming part, where the first and second reforming parts are spaced apart from each other. The holding fixture is in the form of a plate having an area corresponding to a circumference of the internal space of the reformer main body. The first hole portion and the second hole portion are adjacent to each other and are positioned in the holding fixture for first and second reforming parts. The handling apparatus comprises a control hole portion that is overlapped with the first hole portion or the second hole portion. The handling apparatus further includes a handle that is protruded into the handling apparatus through a sidewall of the reformer main body. The reformer main body comprises a poisoning sensor for sensing the poison of the reforming catalyst.