This paper discusses the microscopic mechanism of motional electromotive force, or motional EMF, generated when a conducting rod moves through a magnetic field and cuts magnetic field lines. The establishment of motional EMF in the open-circuit state is analyzed, as well as the dynamic stabilization process of the EMF when the conducting rod forms part of a closed circuit with a steady current. The analysis shows that the Lorentz force is indispensable for charge separation and for maintaining the EMF, although it does no work and does not directly participate in energy conversion or energy transfer. This discussion helps clarify the physical role of the Lorentz force in motional EMF and deepens the understanding of the microscopic origin of electromotive force.