The branch of science which studies the interaction between various forms of matter and electromagnetic radiation is known as spectroscopy. It measures the radiation intensity as a function of its frequency or wavelength. Spectroscopy is used to explain various phenomena in the field of chemistry, physics and astronomy. It also allows the study of the physical and chemical composition of matter at atomic as well as astronomic distances. Spectroscopic techniques can be classified into acoustic spectroscopy, absorption spectroscopy, emission spectroscopy, atomic spectroscopy, nuclear spectroscopy, etc. It is used for various purposes such as measurement of toxic elements in blood, non-destructive elemental analysis, measuring different compounds present in food sample, etc. This book is a compilation of chapters that discuss the most vital concepts in the field of spectroscopy. It presents the complex subject of spectroscopy in the most comprehensible and easy to understand language. This book will provide comprehensive knowledge to the reader.