The book is designed to benefit students and engineers relating to emerging field of RF-MEMS at graduate and post graduate level. It presents a coherent, unified and comprehensive knowledge of the fundamentals of RF-MEMS technology. The aim of the book is to enable the student to get a simplified and satisfactory grasp of the subject. It is written to make students realize that this subject is relevant and useful and also encourage the engineers to develop some facilities in its use. This promising and growing field is of multidisciplinary nature and has diverse applications in various areas like communication, and defense. This book gives an overview of materials, micro fabrication, packaging, market and forecast of RF-MEMS devices and reliability problems of RF-MEMS. It indicates that RF-MEMS will revolutionize with advancement in this technology as it is clearly a technological aspect.The concept is made attractive by giving suitable representative case studies of RF-MEMS, diagrams, and tables. The book will be most useful to not only to students of Physics, Electronics Engineering but also to researchers working in this emerging field.