The monograph discusses issues related to the calculation, application and manufacture of elements of mirror X-ray optics. The issues of its use in plasma diagnostics, X-ray astronomy, micro- and spectroscopy, laser technology are covered. The subject of a separate chapter is the issues of manufacturing technology and methods for controlling X-ray mirrors. For the first time, questions related to the influence of surface characteristics of real mirrors on the characteristics of devices and systems based on them are reflected. Contains a large amount of reference material.