In recent years the fields of both particle physics and astrophysics have become increasingly interdependent. High energy particle physics experiments are ever more difficult and expensive to perform in conventional laboratories and it is apparent that there are sources and accelerators in the cosmos which can be used for experiments which would be impossible on the Earth. At the same time, astrophysicists have found that an understanding of particle physics is essential to describe many observed phenomena (such as dark matter, solar neutrinos and cosmic rays) and also to provide any detailed description of the early universe. In this climate of interdisciplinary research more and more researchers are crossing traditional subject boundaries in order to study what has become known as Particle Astrophysics. This book, conceived as a more specialised follow-up to one of the authors earlier works (Non-accelerator Particle Physics by Klapdor-Kleingrothaus and Staudt) gives a graduate level account of the physics of particle astrophysics. It describes, at an introductory level, the close connection between the microcosm (particles) and the macrocosm (Universe). The approach is wide ranging and succeeds in introducing all of the major theoretical concepts as well as describing the most recent experimental and observational evidence in the field. As such it will be invaluable to anyone approaching the subject from either particle physics or astrophysics.