NOVELTY - A fuel reformer has a modifier (36) which forms hydrogen rich gas (HRG) from a hydrocarbon group fuel supplied by modification reaction. The modifier ejects HRG. A sprayer supplies water atomized from discharge port of modifier. Carbon monoxide (CO) in HRG and water vapor are converted to carbon dioxide and hydrogen by shift reaction and CO reduced gas is formed. A shift portion (20) ejects CO reduced gas.    USE - Used in fuel cell apparatus. (claimed)    ADVANTAGE - Carbon monoxide concentration in hydrogen rich gas is reduced. The expansion of fuel cell apparatus is controlled. Amount of water vapor used by shift reaction is fixed. Energy efficiency is reduced.    DETAILED DESCRIPTION - A fuel reformer has a modifier which forms hydrogen rich gas from a hydrocarbon group fuel supplied by modification reaction. The modifier ejects hydrogen rich gas. Water is atomized from the discharge port of modifier using gas containing hydrogen obtained from downstream side. A sprayer supplies water vapor. Carbon monoxide in hydrogen rich gas and water vapor are converted to carbon dioxide and hydrogen by shift reaction and carbon monoxide reduced gas is formed. A shift portion ejects carbon monoxide reduced gas. The fuel reformer forms hydrogen.    INDEPENDENT CLAIMS are included for the following:    (1) a fuel cell apparatus (10) which has a fuel reformer which forms hydrogen that is supplied to an anode side so an electromotive force can be obtained by electrochemical reaction;    (2) a fuel modification process which forms hydrogen from a hydrocarbon fuel by modification reaction, the modifier accelerating modification reaction which forms hydrogen rich gas from hydrocarbon group fuel. Water is atomized into water vapor. Carbon monoxide in hydrogen rich gas and water vapor are converted to carbon dioxide and hydrogen by shift reaction and a carbon monoxide reduced gas is obtained.    DESCRIPTION OF DRAWING(S) - The figure shows explanatory drawing of fuel cell apparatus. (Drawing includes non-English language text).    Fuel cell apparatus (10)    Shift portion (20)    Modifier (36)    Carbon monoxide selective oxidation portion (38)