This paper describes the design and performance characteristics of two types of refrigerated Molecular Sieve Sorption pump that produces and maintains a pressure of the order of 10 −3 torr in volume of 10–50 l. in case of evacuation of air from atmospheric pressure. The main feature of this method of pumping is its freedom from pumping fluids. Some of its applications along with its limitations are discussed. Applications to multistage sorption pumping and the use of sorption pumps in combination with mechanical dry pump are illustrated.