TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: In (M1), hydrogen is produced by carrying out the reforming reactions upon adjusting the molar ratio of the water vapor with respect to the carbon atoms in the automotive fuel. The molar ratio of the water vapor with respect to the carbon atoms in the automotive fuel is set to greater than or equal to0.1 and less than or equal to7. The reforming reactions are auto-thermal reforming reactions. The reforming reactions are carried out continuously. EXAMPLE - Reforming diesel fuel by autothermal reforming reaction was carried out under the presence of oxygen-enriched air with oxygen concentration of 40%. A continuous type hydrogen production device was used as hydrogen production device and Rh/Al2O3 reforming catalyst was used as the catalyst. AKP-G30LA (RTM; gamma-Al2OP3) (100 g) was suspended in ultra-pure water (200 ml) in a beaker (500 ml). A Teflon (RTM; polytetrafluoroethylene) stirrer piece was placed in the suspension and stirring was carried out quietly for a few minutes under room temperature using a magnetic stirrer. After stirring, the water was removed, and the above operations were repeated three times. The gamma-Al2O3 that was subjected to three repetitions of the above operations was covered to avoid the entry of debris and water was distilled off by vacuum drying at 80degreesC overnight.    After drying, the gamma-Al2O3 was transferred to a preservation container and preserved in a desiccator until use. The dried gamma-Al2O3 (25 g) was weighed out. Rhodium nitrate (Rh(NO3)3) having weight percentage of rhodium metal with respect to the gamma-Al2O3 of 2% was then weighed out. The rhodium nitrate and ultra-pure water (350 ml) were placed in and heated while stirring in a three-necked flask (500 ml), and gamma-Al2O3, which was put in the form of a solution of 60degreesC, was added slowly at small amounts at a time into the three-necked flask (500 ml). After adding the aqueous gamma-Al2O3 solution, stirring at 60degreesC was carried out for 1 hour. Then water was distilled out from the slurry, which was then dried by placing in an oven set at 100degreesC for 12 hours. The dried catalyst was then baked by, placing in electric furnace.    As the liquid hourly space velocity (LHSV) with respect to the catalyst was 0.5 - 20 hour-1, the reforming reaction was carried out at LHSV 2.3. Air was used as background gas and as the air to fuel (A/F) ratio with respect to the diesel fuel was 2-20, the ratio of A/F was set at 4. The reforming reaction was carried out at 500-1000 (preferably at 800)degreesC.    A control reforming method was conducted by autothermal reforming reactions carried out using ordinary air with oxygen concentration of 21%. The oxygen concentration for control method was lower than for the test method. The hydrogen yield (mol%) for test/control method at water vapor/carbon molar ratio of 1, 3 and 4.5 was 95/42; 110/41; and 120/40 respectively. The results showed that the test method produced hydrogen efficiently even under conditions of low A/F as compared to the control.