In the majority of the papers dealing with the status and prospects of the development of exobiology a theoretical analysis predominates. More attention should be given to the discussion of methods and experiments carried out at the present time or planned for the near future. In investigating life in the cosmos, we attach considerable interest to detection of compounds specific to living beings, in particular, organic compounds of phosphorus, porphyrins, amino nitrogen and others. In searching for microorganisms on other planets and in interplanetary space the greatest danger is that, as a result of errors in technique, the investigator will detect earthly microorganisms which have invaded and reproduced in the nutrient mediums used. Information on the vitality of microbes detected in the ground taken in the zone of eternal frigidity, in big pieces of rock salt, in meteorites, etc. confirms these apprehensions. Initially, search for heterotrophic bacteria should be carried out, then for phototrophic, denitrifying, sulfate-reducing, nitrogen-fixing microorganisms, as well as bacteria oxydizing sulfur, iron, methane and hydrogen. Instruments for detection of cosmobionts can be based on nephelometry, potentiometry, manometry and on the use of carbon labelled compounds and added to the nutrient medium. Investigations elucidating the influence of low and high temperatures, vacuum, and radiation on living cells are possible to carry out on earth and therefore are most accessible to exobiology. They give interesting results and in some degree make it possible to approach the study of the conditions to which life would be exposed in space. The sterilization of space ships is of paramount importance for further exobiological investigations. Under space conditions microbes will not completely perish on the space ship surface and, therefore, careful sterilization is necessary. The assertion that earth microbes, having reached the lunar surface, will not be able to develop is not free of objections. To carry out sterilization so that space ships will not contain dead bodies of microbes is impossible. Therefore, the wish expressed sometimes that "carcasses" of microbes should not be conveyed onto other planets is practically unrealizable.