This book reviews the resonant interaction between electromagnetic field/light and electrons/matters in a nanometric volume for the first time to invite the readers to a new field of nano-photonic/electronic science and technology. Especially, the unique feature of this book is to introduce the concept of nano-optics, i.e., near field optics into discussions on mesosopic systems. This book will enable undergraduate and graduate students, junior scientists, and engineers to systematicaly study the physics, diagnostics, and fabrication on nano-sized materials and devices.