In this final thesis the primary roles of the inert gas system on ships for the transport of crude oil and oil derivatives are described, as well as the dangers that threaten ships for the transport of the above types of cargo. The purpose of the inert gas system stems from the existing danger, which is the prevention of explosion occurrence in cargo tanks by creating an inert atmosphere with inert gas. The main divisions of the design characteristics of the inert gas system are listed, but considering that in practice the ve rsion with a combustion chamber and the version with a combustion chamber in combination with the use of exhaust gas steam generators are most often used, the aforementioned two versions are elaborated in detail in separate chapters of the thesis while th e other versions are only mentioned. The components of the inert gas system are described with a graphic representation, and their principles of operation are listed and described. In addition, the operation of the inert gas system is shown, i.e. the diffe rent modes of operation of the system during the operation with the cargo are shown. An example of the optimization of the system in operation with the aim of reducing the emission of exhaust gases, and therefore environmental pollution, is given and shown by calculation.