The monograph describes the modern understanding of the evolution of structural and phase states of dislocation substructures and the fracture surface at high-cycle fatigue of stainless steels of different structural classes. Modern methods of physical materials and primarily scanning and transmission electron microscopy, the analysis of changes in fine defect substructure and the fracture surfaces of fatigue during normal processing conditions and low energy electron beams, significantly increases the fatigue life are discussed. The physical mechanisms of increasing fatigue life are discussed.