This handbook, which builds on the previously published book, Magnetic Material for Motor Drive Systems, focuses on how to use magnetic material for electrical motor drive systems, especially electrical vehicles and power electronics. The volume is aimed at researchers and engineers working towards the realization of more efficient and down-sized motor drive systems by utilizing magnetic materials with complex properties based on the operation of motors and power electronics. The magnetic materials and the motor drive system have mutual interactive characteristics due to electromagnetically coupling with the same current and voltage, so it is extremely important to have both viewpoints. In this handbook, for that purpose, the fundamental concepts of electrical engineering and magnetic science and engineering are described in detail. At the same time, in order to develop new materials from the viewpoint of motor drive systems and to utilize the magnetic material, this handbookwidely discusses the multi-scale analysis technology that traces back to the magnetic domain structure and first-principles calculations, the basics of current materials and new magnetic materials, the fundamental magnetic measurement technology of magnetic material, and the application of magnetic technology. It is expected that the knowledge gained through this title will greatly contribute to the coming EV society.