A new method is proposed to disclose the role of each component in a chemical process system. There are many methods for analyzing a process system from energy viewpoints. But these viewpoints cannot be applied to the behavior of each chemical component especially related to environmental problems, because the energy of such a dilute component is negligibly small as compared with that of the main component, Hence, a new diagram with ordinate of ln p(j) and abscissa of n(f)RT(0) for component j is proposed and it is called a material-utilization diagram. The relationship between this diagram and the energy-utilization diagram is demonstrated from the entropy production.