Widespread introduction of automation and robotics in various branches of the national economy has caused intensive growth of production of low-power electric machines. Due to high specific consumption of magnetic materials in production of micromachines, the development of waste-free technology of manufacture of magnetic cores and cores by methods of powder metallurgy is a very promising direction. Use of magnetically soft materials (MMM) produced by powder metallurgy methods allows to reduce losses of electrical steel up to 60% and exclude many labor-intensive operations, automate the technological process and provide the necessary precision of parts dimensions, excluding further finishing machining. In this monograph the main characteristics of magnetic-soft materials, the influence of composition and structure on their properties, magnetic-soft composite materials and composition, structure and properties of MMM used in the production of magnetic cores and cores in electric machine building are considered and studied.