Book excerpt: Time of flight secondary ion mass spectrometry, TOF-SIMS, is a highly surface sensitive analytical technique that provides information about composition with submicron lateral resolution. For select materials, TOF-SIMS provides unparalleled sensitivity along with excellent reproducibility, and as a mass spectrometric technique, it also provides excellent specificity. 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. Given a basic background in undergraduate chemistry and physics, the book will be of use to any student with an interest in the technique.