Disclosed are a method for inexpensively reducing the contact resistance between an electrode and an organic semiconductor upon a p-type operation of the organic semiconductor; and a method for inexpensively operating, as an n-type semiconductor, an organic semiconductor that is likely to work as a p-type semiconductor. In addition, also disclosed are a p-cannel FET, an n-channel FET, and a C-TFT which can be fabricated inexpensively. Specifically, a p-type region and an n-type region is inexpensively prepared on one substrate by arranging an organic semiconductor that is likely to work as a p-type semiconductor in a p-channel FET region and an n-channel FET region of a C-TFT; and arranging a self-assembled monolayer between an electrode and the organic semiconductor in the n-channel FET region, which self-assembled monolayer is capable of allowing the organic semiconductor to work as an n-type semiconductor.