Energy problems in the world require more efficient use of energy. Thus, in recent years there has been a significant increase in scientific studies on energy efficiency. Approximately 80% of world trade is carried by sea. Therefore, transportation of such a big volume requires large-scale energy consumption. For this reason, energy efficiency is very important in the maritime sector. The International Maritime Organization (IMO) which is the authority on maritime transport in the world executes obligations and recommendations for energy efficiency and environmental pollution issues. An important method of scientifically measuring energy efficiency is exergy analysis. It is observed that the performance analysis by exergy method is not applied to the shipping sector sufficiently, so this paper is tried to fill this gap in maritime area. In this article, the performance of the combined power system of a container ship is analyzed by the exergy method. According to the obtained results, the total exergy efficiency of the system is observed to be 49%.