The author provides, in nine chapters, a compact and up-to-date coverage of the entire range of applications of the two most important ion traps: the Paul('radiofrequency') trap and the Penning('dc) trap. The book begins with full details of the ion confinement principles of both these traps; this is followed by a presentation of the basic experimental techniques, including details of a few actual traps. There is then a chapter on the methods of ion cooling, now an essential integral part of all trap-based experiments. The next four chapters provide a comprehensive coverage of applications in four major areas, broadly classified as: atomic physics, frequency standards, collision studies, and analytical mass spectrometry. The text is appended by a set of more than 600 fully titled chronologically arranged references which mirror the growth of the field as well as providing a comprehensive guide to original research papers. The text should be useful to students both at the senior undergraduate and beginning graduate level as a general reader for professionals in atomic physics, chemical physics, mass spectometry and related fields.