Typical polypropylene (PP) foam is manufactured using random PP, but the mechanical properties of PP foam can be improved when homo PP, which is more crystalline than random PP, is used. However, the increase in the crystallinity of such a material causes various process difficulties in manufacturing the foamed foam by lowering the workability. In this study, homo PP was applied in the process of making PP foam by using electron beam crosslinking and chemical foaming agent using polypropylene which is the most used for automobile interior and exterior materials. The degradation of the workability in the process was overcome by the optimization of electron beam crosslinking process and side feeding systems.