Energy transformation is discussed from the viewpoint of the intermediary energy released or accepted by a change of substance. To display the results on a microscopic EUD (Energy-Utilization Diagram), the internal transformation in the process itself and the external transformation between different processes are demonstrated separately. The method is applied to two kinds of exothermic reactions and an endothermic reaction, energy-conserved processes with Delta H=0 such as heat conduction, pressure drop and osmotic pressure and the energy transformation in the electrolyte in a fuel cell. It is found that this method reveals the internal mechanisms in complex energy transformation quite clearly.