In this paper, high-voltage SF6 circuit breakers are analyzed - their origin, history, use and production. The method of handling SF6 gas, safety during work and the chemical structure of SF6 gas are described. A comparison of the characteristics and capabilities of different types of high-voltage SF6 circuit breakers, manufactured by Koncar, Siemens and ABB, was performed. The comparison was made by types of SF6 switches and by voltage levels. An analysis of the reliability of SF6 switches manufactured by Koncar was also performed based on data on their failures.