Several generations of scientists consistently are fluidize more and more low-temperature gases. In the end of XIX century was fluidize hydrogen which was last from «constant» gases. The difficult problems of liquefaction and analysis of helium appears in connection with his opening. It took an essentially new approach to the organization of cryogenic maintenance of experiments. About works of Kamerlingh Onnes in Leiden’s university on liquefaction of helium — the first quantum liquid is told. At areas of helium temperatures he had been carried out the researches which have allowed to open such effect as superconductivity of metals. Afterwards a superfluidity of liquid helium and was discovered and others effects which not expound by classic classical physics. Results of the basic researches executed by Kamerlingh Onnes and his employees, considerable influenced on development of new physics, have expanded a representations about properties of matter.