The book discusses theoretical and practical issues of development and operation of oil-free vacuum pumps, which, due to their principle of operation, do not pollute pumped objects with oil vapors and decomposition products. Their technical and economic characteristics are given, the main advantages and disadvantages are shown. Particular attention is paid to cryogenic pumping methods in a wide range of pressure changes. The basics of cryogenic vacuum pumps calculation and the most rational designs are presented. Relevant cooling systems are described. The book is intended for engineering workers of factories, research institutes and laboratories involved in the design and operation of oil-free pumping facilities.