If an organic transistor is formed by printing with a low cost, there are problems in that an inexpensive electrode material has a high contact resistance with a semiconductor, and an expensive electrode material has a low contact resistance. To solve the problems, the present invention provides an organic transistor and a method of forming the same, the organic transistor being formed with a lowmaterial cost and low manufacturing cost and providing a low contact resistance with a semiconductor and high performance. The organic transistor has electrodes whose bodies are formed mainly of an inexpensive first metal and whose surfaces are formed of a second metal that is expensive but provides high performance properties. To obtain stability of this structure with a low cost, the present invention uses a property of the second metal, in which the second metal is easily segregated on the surface of the first metal in an alloy of the first metal and the second metal.