Ion implantation has become a basic technology in device manufacturing. For efficient use of this accelerator-based technique the choice of appropriate ion sources is important. This book deals with the design and operation of ion sources. Additionally the physics of ion formation of the various elements with different charge states and charge neutralization are discussed. Ion selection and beam diagnostics are part of the book too. The presentation of the necessary equations and diagrams for the various parameters makes this book useful as a handbook for ion sources.