This book is the second edition of a seminal reference work on the topic of optical inspection methods for microsystems that was first published in 2007. In 17 chapters, the authors detail the working principles of various optical methods for examining the surface quality of microsystems, as well as the advantages, drawbacks and applications of each method. The target audience is any producer of microsystems, including MEMS and other microcomponents, hence primarily industrial users and applied research labs. In comparison to the first edition, which was dedicated to describing then state-of-the-art surface characterization methods, the new edition also addresses new demands such as checking the system’s internal parts after packaging, reduced measurement uncertainty and new requirements for calibration of measurement tools. This book should be an essential reference on the shelf of any microsystem manufacturer.