This manual is a continuation of educational materials on the physics of semiconductors, which considers the volumetric properties of semiconductor materials and methods of their study. The manual considers the classification of surface electronic states, provides an introduction to phenomenological surface theory and describes the main surface properties of semiconductors. Particular attention is paid to modeling the most important electrophysical characteristics of the near-surface region of the semiconductor's spatial charge, since it is these characteristics that determine the operating parameters of TIR transistors and other field semiconductor devices , active region of which is the near-surface region of the semiconductor. The materials of the training manual are prepared for independent and practical classes on the course "Physics of semiconductors" , which is read for 3rd year students, students in the specialty "Microelectronics and semiconductor devices", However, it may also be of interest to students of other physical specialties.