TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: In the dehydrogenation catalyst, when the alumina layer is divided equally into three parts in the layer thickness direction and the parts are designated as first region, second region and third region in order from the outside, the mass ratio of platinum atoms to aluminum atoms in the first region (C1), the mass ratio of platinum atoms to aluminum atoms in the second region (C2), and the mass ratio of platinum atoms to aluminum atoms in the third region (C3) satisfy the relationship in the following formulas (i) and (ii): C1 is greater than C2 (i); and C1 is greater than C3 (ii). Preferred Components: The platinum solution contains bis(ethanolammonium)hexahydroxo platinate (IV). In the alumina carrier to be subjected to the immersion step, the specific surface area of the alumina layer is greater than or equal to 200 m2/g, and the proportion of pores with a pore diameter of 1-10 nm in the total pores possessed by the alumina layer is greater than or equal to 60%. Preferred Method: The calcination temperature in the calcination step is 320-380 degrees C. EXAMPLE - Anodic oxidation was performed to aluminum plate in 0.1-0.3 M oxalate solution under conditions of 40-60 degrees C and 30-50 V for 1-2 hours. Then, the plate was subjected to hot-water treatment by immersion in boiling pure water for 5-6 hours and finally calcined under conditions of 500 degrees C for 3 hours to obtain alumina carrier with alumina layers of 15-30 mu m in thickness formed on each side of the aluminum plate. The alumina carrier was immersed in bis(ethanolammonium)hexahydroxo platinate (IV) aqueous solution (platinum concentration: 25 g/l) for 10 seconds, and then dried under conditions of 120 degrees C for 1 minute. Then, the carrier was calcined under conditions of 270 degrees C for 20 minutes to obtain dehydrogenation catalyst (test). A control catalyst was prepared as follows: an alumina carrier obtained in a similar manner as the test was immersed in tetraammineplatinum nitrate solution (platinum concentration: 53 g/l) for 2 hours, and then dried under conditions of 120 degrees C for 10 minutes. After calcination, the carrier was immersed again in tetraammineplatinum nitrate solution (platinum concentration: 53 g/l) for 2 hours and calcined under conditions of 300 degrees C for 20 minutes to obtain control dehydrogenation catalyst. The test/control dehydrogenation catalysts were evaluated for platinum distribution. The results for test/control catalyst were: mass ratio C1 in the first region for test/control was 0.19/0.23; mass ratio C2 in the second region for test/control was 0.12/0.38; and mass ratio C3 in the third region for test/control was 0.04/0.17 respectively. The test/control dehydrogenation catalyst when used in dehydrogenation reaction of methylcyclohexane (MCH) showed MCH conversion ratio for test/control of 40%/34% (after 1 hour); 37%/32% (after 3 hours); 34%/29% (after 5 hours); and 32%/28% (after 7 hours).