This book provides an overview of nanoscale electrochemistry in the context of well-established concepts and principles of electrochemistry. It presents fundamental theory with the emphasis on differences between charge-transfer and mass-transfer processes on the nanoscale and analogous reactions occurring at macroscopic electrochemical interfaces. The rigorous theoretical treatment enables readers to gain an in-depth understanding of nanoelectrochemical systems discussed. The book also covers modern electrochemical tools and techniques that enable the fabrication and characterization of electrochemical systems on the nanometer scale.