Particle physics is the science that pursues the age-old quest for the innermost structure of matter and the fundamental interactions between its constituents. Modern experiments in this field rely increasingly on calorimetry, a detection technique in which the particles of interest are absorbed in the detector. Calorimeters are very intricate instruments, their performance characteristics depend in subtle, sometimes counter-intuitive ways on design details. This book, written by one of the world's foremost experts, is the only comprehensive text on this topic. It provides a fundamental and systematic introduction, in which many intriguing calorimeter features are explained. It also describes the state-of-the-art, both for what concerns the fundamental understanding of calorimetric particle detection and the actual detectors that have been or are being built and operated in experiments. In the last chapter, some landmark scientific discoveries in which calorimetry has played an important role are discussed. This book summarizes and puts in perspective work described in some 900 scientific papers, listed in the bibliography. This second edition emphasizes new developments that have taken place since the the first edition appeared (2000).