ET is a new type of switching device used controlled tunneling of electron to amplify current. According to Moor’s law, SET may be alternative of complemented metal oxide semiconductor (CMOS) device for the next generation electronic devices and sensors. This is a review article intended to consolidate the knowledge on the working principle of SET along with relevant other aspects and also highlighting the promising applications with limitation of implementations in the 21st century in order to reduce power dissipation.