Time of flight secondary ion mass spectrometry, TOF-SIMS, is a highly surface sensitive analytical technique that can provide information about composition with submicron lateral resolution for a wide variety of materials. In conjunction with the latest cluster ion sources, organic depth profiling is also commonly performed now. For select materials, TOF-SIMS provides unparalleled sensitivity along with excellent reproducibility, and as a mass spectrometric technique, it also provides excellent specificity in the identification of many organic materials. Of the analytical methods available, it is among the most surface sensitive, but the physical principles that underlie it are also the least understood. This volume describes the instrumentation, the physical principles behind the technique to the extent they are understood, and provides a practical approach for the interpretation of TOF-SIMS data. The use of advanced data processing methods such as multivariate statistics are described in a readily approachable manner along with guidelines to help the reader understand where they are or are not really helpful. Given a basic background in undergraduate chemistry and physics, the book will be of use to any student with an interest in the technique. While the analyses are in fact performed in a vacuum, they are conducted in the context of a wider laboratory environment where many other analytical methods are available. The place of TOF-SIMS amongst them, when it is appropriate to use this method or another, or when multiple methods should be used in conjunction with TOF-SIMS is discussed in some depth. Examples of the wide range of applications of TOF-SIMS for research and problem solving in Academic Laboratories, National Laboratories, and Industrial laboratories, as it is applied to polymeric, biological, semiconductor, metallic, insulating, homogeneous, and inhomogeneous surfaces are described.