pThis textbook provides a comprehensive and didactic introduction from the basics to the current state of the art in the field of EEGMEG source reconstruction. Reconstructing the generators or sources of electroencephalographic and magnetoencephalographic EEGMEG signals is an important problem in basic neuroscience as well as clinical research and practice. Over the past few decades, an entire theory, together with a whole collection of algorithms and techniques, has developed. pIn this textbook, the authors provide a unified perspective on a broad range of EEGMEG source reconstruction methods, with particular emphasis on their respective assumptions about sources, data, head tissues, and sensor properties. An introductory chapter highlights the concept of brain imaging and the particular importance of the neuroelectromagnetic inverse problem. This is followed by an in-depth discussion of neural information processing and brain signal generation and an introduction to the practice of d