This book examines single-electron circuits as an introduction to the rapidly expanding field of nanoelectronics. It discusses both the analysis and synthesis of circuits with the nanoelectronic metallic single-electron tunneling (SET) junction device. The basic physical phenomena under consideration are the quantum mechanical tunneling of electrons through a small insulating gap between two metal leads, the Coulomb blockade and Coulomb oscillations — the last two resulting from the quantization of charge. The author employs an unconventional approach in explaining the operation and design of single-electron circuits.