The metal organic chemical vapor deposition (MOCVD) process is widely used to form a multi-layered structure with thin films for diverse semiconductor materials. The MOCVD process is the most promising method for manufacturing chips that are based on the compound semiconductor, but its technology is partly still insufficient. If a device, for example, lacks a non-uniformity related to the composition and thickness of the film, it decreases the reliability of the final product and affects the economics. To ensure that the equipment is competitive in the worldwide markets, a high reliability including the controllability of compositions is required for the equipment. In this study the CFD analysis was used to investigate the behavior of the process gas in a MOCVD reactor where the process gases including the component of the GaN films are injected as separated through a multi-module showerhead for eventually targeting multi-component films such as AlGaInN materials. After applying of Porous Media, a stabilization of process gas was confirmed from the results of pressure distribution.