An energy management system that achieves minimization of electric power costs and leveling of an electric power demand while securing necessary battery residual quantity. The energy management system includes a charging stand that supplies electric power to an electric vehicle (EV) as an electric power supply part, a reservation information acquisition unit that acquires reservation information on electric power reception of the EV in the charging stand before the EV arrives at the charging stand, a charging plan preparation unit that predicts an electric power demand in the charging stand and prepares a charging plan for the EV based on the reservation information, and a charging controller that controls electric power supply for the EV in the charging stand based on the charging plan.