An introduction to time of flight secondary ion mass spectrometry (ToF SIMS) and its application to materials science This book highlights the application of Time of Flight Secondary Ion Mass Spectrometry (ToF SIMS) for high resolution surface analysis and characterization of materials. While providing a brief overview of the principles of SIMS it also provides examples of how dual beam ToF SIMS is used to investigate a range of materials systems and properties. Over the years SIMS instrumentation has dramatically changed since the earliest secondary ion mass spectrometers were first developed. Instruments were once dedicated to either the depth profiling of materials using high ion beam currents to analyse near surface to bulk regions of materials (dynamic SIMS) or time of flight instruments that produced complex mass spectra of the very outer most surface of samples using very low beam currents (static SIMS). Now with the development of dual beam instruments these two very distinct fields now overlap.