For the high temperature operation of a single electron transistor, the nano fabrication process is the most important key technology. For the complete room temperature characteristics of the single electron transistor, such as a room temperature Coulomb diamond characteristics, 1 to approximately 2 nm feature size is indispensable. The conventional nano fabrication technology, however, could not attain such a small feature size of 1 to approximately 2 nm. A carbon nanotube is one of the best candidates for the nano-scale devices because of its small features size, e.g., the single wall carbon nanotube has a diameter of 1 to approximately 2 nm. Application of such a small feature of a carbon nanotube to a single electron transistor could be expected to increase the Coulomb energy and also to raise the operation temperature up to 300 K. However, the control of the precise positioning of the carbon nanotube for the device application has been so far a quite hard work and has been almost impossible. Only some primitive techniques were succesfully achieved. In the present paper, we proposed the new technology that could easily control the position of the carbon nanotube by using the patterned chemical catalyst. The carbon nanotube can be grown between the patterned chemical catalyst using the thermal CVD process. The single electron transistor was fabricated using the position controlled grown carbon nanotube as a channel and its electrical properties were examined. The single electron transistor showed the Coulomb diamond characteristics even at room temperature. The Coulomb energy is 400 meV and corresponding Coulomb temperature is as high as approximately 5000 K.