NOVELTY - Coil shaped reaction containers such as desulfurizer, modifier (3), carbon monoxide transformation device (9) and carbon removal device (10), surround combustion space in the hydrogen generator (1) in concentric manner and in order.    USE - For generating hydrogen rich gas by steam reforming of town gas, for supply to fuel cell.    ADVANTAGE - Since the reaction containers have coil shape, the cross section of the gas passageway is smaller and the channeling of the gas inside the hydrogen generator is eliminated. Temperature distribution is made uniform and heat exchange with combustion gas is made favorable. Each reaction is performed smoothly. The surplus heat in each reactor container is collected and effectively used. Each reaction container can be controlled to optimal temperature. Provides high thermal efficiency and provides a simple and size reduced structure due to the concentrically arranged reaction devices.    DETAILED DESCRIPTION - The combustion burner (6) is placed at the center of the combustion space. The outer diameter of the reaction coil of the modifier is made smaller than the coil internal diameter of the carbon monoxide transformation and removal devices. A heat insulator (8) is arranged between the modifier and the transformation device (9). Gas outlet of the reaction coil of the modifier is positioned near the heater having the burner. The gas flow direction from the inlet of the reaction coil of the modifier, opposes the flow direction of the combustion gas of the heater. Gap is provided between the pipes comprising the reaction coils of the desulfurizer, modifier, carbon monoxide transforming and removal devices. A space for flow of combustion gas is formed between the outer wall (7) which surrounds the modifier and the modifier.    DESCRIPTION OF DRAWING(S) - The figure shows a cross sectional view of the hydrogen generator. (Drawing includes non-English language text).    hydrogen generator (1)    modifier (3)    combustion space (5)    burner (6)    outer wall (7)    heat insulator (8)    carbon monoxide transforming device (8)    carbon monoxide removal device (10)