The purpose of this book is to introduce the reader to the fundamental concepts of Fourier Transform Infrared (FTIR) spectroscopy. The discussion assumes no previous background in FTIR, but a familiarity with the basic concepts of chemistry and physics will be helpful in understanding this text. This book teaches the basics of FTIR to those new to the €eld, and will serve as an excellent reference guide for experienced users. All terms shown in italics will be de€ned in the glossary at the end of the book.