The near future is of Nanotechnology. This field is going to revolutionize the every domain of science and affect the day to day life of human being from what we eat, medicine, to the advance communication system to space technology. As far as nanoelectronics is concern a very promising devices are Single Electron Devices where in place of simple conduction tunneling is dominated and quantum effects describe the behavior of device. Single Electron Transistor [SET] is a single electron device that is most probably going to check the dominance of CMOS in the current electronics industry. SETs have recently attracted much attention because of there nano feature size, ultra low power dissipation, new functionalities and CMOS compatible fabrication process. It also appears that CMOS and SETs are rather complementary. This book enlighten nanotechnology future scope with special emphasis on nanoelectronics.