NOVELTY - A hydrodesulfurization device integrated cylindrical type water vapor modifier comprises cylindrical type water vapor modifier and hydrodesulfurization device (100).    USE - A hydrodesulfurization device integrated cylindrical type water vapor modifier for supplying fuel hydrogen to solid oxide fuel cell (SOFC) and carbon monoxide to polymer electrolyte fuel cell (PEFC).    ADVANTAGE - The modifier is more compact, maintains target temperature without requiring heating unit, suppresses heat radiation, and prevents decline in modification efficiency.    DETAILED DESCRIPTION - A hydrodesulfurization device integrated cylindrical type water vapor modifier comprises cylindrical type water vapor modifier and hydrodesulfurization device (100). The cylindrical type water vapor modifier comprises cylindrical body which consists of first cylinder (1), second cylinder (2) and third cylinder (3) positioned at intervals concentrically, burner positioned at radial direction central part of first cylinder, modification-catalyst layer filled with modification catalyst to interval divided into radial direction with first cylinder and second cylinder, carbon monoxide modifying catalyst layer and carbon monoxide removal catalyst layer provided between interval of second cylinder and third cylinder of upper position of modification catalyst layer, and heat insulating material layer (101) positioned on outer periphery of third cylinder. The carbon monoxide modifying catalyst layer is formed in interval which reverses flow-path direction in end of axial direction with respect to modification-catalyst layer. The hydrodesulfurization device comprises hydrogenation catalyst layer, first adsorption agent layer and second adsorption agent layer positioned on outer periphery of heat insulating material layer.    DESCRIPTION OF DRAWING(S) - The drawing shows an explanatory view of cylindrical type water vapor modifier. (Drawing includes non-English language text).    First cylinder (1)    Second cylinder (2)    Third cylinder (3)    Hydrodesulfurization device (100)    Heat insulating material layer (101)