Although the ability of some microorganisms to grow without O(2) has long been recognized, the application of new methodologies has greatly expanded the known diversity and potential of anaerobic microorganisms and processes. In particular, anaerobic techniques that permit the successful cultivation of microorganisms on solid media have opened new avenues for the study of the physiology and metabolic potential of many new microorganisms using molecular, genomic, and proteomic tools. One technique above all has proven instrumental for anaerobic studies over the years: the use of the anaerobic chamber. This unit gives a brief description of the methods used for the cultivation of anaerobic microorganisms, and describes in detail the principles and applications of anaerobic chambers, with special emphasis on vinyl glove boxes. The methodologies described in this unit should provide the interested but inexperienced investigator with the basic tools to successfully cultivate anaerobic microorganisms and study anaerobic processes.