Spintronics is a promising technology as one of the alternatives to the traditional memory technology. MRAM is one of the major applications of Spintronics. The authors offer the first comprehensive book on MRAM. It is structured to be a complete and updated guide for the readers. This book provides an overview of the state of the art, describes industrial applications, and presents original technologies in this rapidly-moving field. It covers aspects from physics, device, circuit, and system to application of MRAM. The book provides the necessary skills, tools and guidelines for different-level MRAM designers. It also summarizes the challenges and prospects of MRAM.