An EMM (Energy Monitoring and Management) control system performs energy management of buildings, each building having an EMM client disposed therein. The EMM control system includes an EMM server configured to receive operation information of energy-consuming equipments in the building and information related to energy and environment of the building from the EMM client to perform a function of analyzing/taking statistics/reporting for the operation information, and energy and environment information, an EOM (Energy Optimization and Maintenance) server configured to derive an optimum energy operation program through energy evaluation index and simulation from the information provided from the EMM client and providing the optimum energy operation program to the EMM client.