Happiness machine is a testing device that test the individual’s emotional level and gives a correct picture of his state of mind. It is invented by Biswaroop Roy Chowdhury, Atal Bihaari Mallik and B K Chandra Shekhar. It measured the happiness level based on the skin resistance of the body which is inversely proportional to the frequencies of brain waves created by various thoughts of mind. This machine is aimed to measure the state of mental thoughts (negative or positive). This machine tells whether a person is in learning state of not.