NOVELTY - A combustor (8) generates combustion gas and outputs to modifier (14). The modifier ejects the exhaust gas, after vaporizing and reforming, fuel consisting of alcohol, dimethyl ether or any other hydrocarbons using combustion gas to form reformed gas containing hydrogen. A circulation unit circulates the exhaust gas from modifier again to combustor during startup.    USE - For fuel reformer of movable type fuel cell system for electrical power units, especially of electric vehicle.    ADVANTAGE - By circulating the exhaust gas again to combustor, the emission of unburnt methanol or formaldehyde is inhibited and high power is not needed for supplying air to the burner. Also by using elimination gas treatment equipment, the intermediate product or nitrogen oxide or unburnt fuel in exhaust gas is treated, and hence the emission of unburnt methanol or formaldehyde from fuel cell is inhibited.    DETAILED DESCRIPTION - The circulation unit has a blower (7) which supplies air to combustor and comprises three valves. A valve (101) is arranged on circulating flow path (100) of the exhaust gas from modifier, on upstream side of blower. Another valve is arranged on elimination gas flow path (18) of exhaust gas on the downstream side of the modifier, and the third valve is arranged on air intake flow path (6), on upstream side of blower. During startup of combustor, the valve (101) is opened to circulate the exhaust gas from modifier, again to combustor and other two valves are closed. When the burner reaches a predetermined temperature, the valve (101) is closed to stop circulating exhaust gas to combustor and the exhaust gas is ejected externally and the other two valves are opened. An elimination gas treatment equipment may be provided on gas emission path (18) to treat the intermediate product, nitrogen oxides or unburnt fuel in the gas which is ejected to the elimination flow path of exhaust gas, from modifier.    DESCRIPTION OF DRAWING(S) - The figure shows the block diagram showing the burner for reforming machines. (Drawing includes non-English language text).    Air intake flow path (6)    Blower (7)    Combustor (8)    Modifier (14)    Elimination gas flow path (18)    Exhaust circulating flow path (100)    Valve (101)