Protein-mediated charge transport is of relevant importance in the design of protein-based electronics and in attaining an adequate level of understanding of protein functioning. This book reviews a variety of experiments devoted to the investigation of charge transport in proteins and presents a unified theoretical model to interpret macroscopic results in terms of the amino acids backbone-structure of the single protein. It aims to serve a broad audience of researchers involved in the field of electrical characterization of biological materials and in the development of new molecular devices based on proteins and also as a reference platform that surveys existing data and presents the basis for future development of a new branch of nano-electronics, which by mixing proteomics, that is, the large-scale study of proteins, particularly their structures and functions, and electronics is introduced here as proteotronics.