Future particle accelerators of higher energy and intensity will have the potential to increase the available flux of slow muons by nearly three orders of magnitude. Therefore a new era in the study of elementary particles is expected. This book reviews the state of the art in the field of exotic atoms in condensed matter. It covers the applications and perspectives of muon- and pion-based analysis of structural, magnetic and superconducting properties in the solid state. Also, spectroscopic applications of exotic atoms to chemical analysis are presented. One section is devoted to muon-catalyzed fusion. This unique book fills a gap and is a must for every researcher in the field.