A centrifugal turbo compressor used in industry is a fluid machine that converts mechanical energy into fluid pressure and kinetic energy. It consists of an impeller that rotates at a high speed to accelerate the air, a diffuser that increases the pressure by diffusing the accelerated air, and a volute that collects the diffused gas and directs it to the outlet. This paper reports that the numerical analysis of the centrifugal turbo compressor at 3rd stage using ANSYS CFX. Based on the analysis results, the aerodynamic performance and flow characteristics were evaluated. Also, it was verified by comparing with experimental data.