This introductory course covers the fundamentals of X-ray photoelectron spectroscopy (XPS), which is the most widely used and important method for chemically analyzing surfaces. This class is intended for scientists, engineers, and technicians who would like both a basic, working knowledge of the technique and the ability to understand and interpret XPS data, including survey and narrow scans. XPS is an important tool for understanding surfaces in many areas of technology, including in semiconductor manufacturing, failure analysis, thin film deposition, tribology, wetting, biosensors, coatings, catalysis, and electrochemistry. After taking this course, the student should understand the basic physics of XPS and how an XPS instrument works, including how X-rays are generated, why XPS is surface sensitive, the fundamental equation of XPS, how spin-orbit splitting dictates the type of peaks that are present in a spectrum, and the nomenclature of XPS (and Auger) lines. The student should also be able to identify/calculate the elements that are present at a surface, their concentrations (with appropriate caveats), and be able to understand some basic peak fitting.