NOVELTY - The system has a modification-catalyst layer, carbon monoxide (CO) modifying catalyst layer (22) and CO removal catalyst layer (36) that are integrated and arranged in a cylindrical container. A partition plate (51) is provided between CO modifying catalyst layer and CO removal catalyst layer. The partition plate (54) is arranged between the partition plate (51) and CO modifying catalyst layer. A guard catalyst unit de-sulfurizes sulfur content in interflow of raw fuel and water vapor at inflow side with respect to modification catalyst layer.    USE - System for pre-processing interflow of raw fuel of hydrocarbon type and water vapor in integrated multiplex cylindrical-type steam reforming device for fuel hydrogen production of fuel cell such as polymer electrolyte fuel cell (PEFC) and solid oxide fuel cell (SOFC). Can also be used in methane, ethane, propane, butane, town gas, liquified petroleum gas, natural gas, petrol, kerosene and methanol.    ADVANTAGE - The steam reforming device adhering to modification-catalyst surface in steam reforming device is eliminated, without decomposing the higher hydrocarbon. The performance decrement the modification catalyst can be prevented. The usage-amount of higher-hydrocarbon adsorption agent can be suppressed. The low cost of capacity enlargement of the pre-processing system can be restrained and carried out entirely. The poisoning of the modification catalyst by the sulfur content can be prevented for a long period of time. The poisoning according the modification catalyst in a modification-catalyst layer to the sulfur content for a long period of time can be prevented. The deterioration can be prevented. The maintenance free of the steam reforming device for fuel hydrogen production of fuel cell can be achieved.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view illustrating the integrated multiple cylindrical steam reforming device. (Drawing includes non-English language text)    CO modifying catalyst layer (22)    Air supply pipe for CO removal (30)    CO removal catalyst layer (36)    Reformed gas outlet tube (40)    Partition plates (51,54)