A power demand/supply management server which is connected through a communication network to a plurality of power operating devices for controlling electrical equipment and which is adapted to distribute control information defining control contents for the electrical equipment to the power operating devices, the power demand/supply management server comprising: a memory unit that is adapted to store a predetermined energy consumption model for predicting an electricity daily load curve indicating an electrical power consumption per predetermined time using parameters which are control-target equipment information of the power operating devices, applied-rate-plan group information indicating an electricity unit meter-charge applied to the power operating devices and an applied period of the electricity unit meter-charge, and control contents to the electrical equipment and a forecasting value relating to a future weather condition; an information obtaining unit that is adapted to obtain control preference information including cost evaluation values which are barometers indicating a compatibility of restraint conditions to a comfort and an electricity bill for each consumer, the comfort and the electricity bill being set and input by the power operating devices; a control simulating unit which is adapted to obtain the energy consumption model from the memory unit in order to calculate the electricity daily load curve, and which is adapted to simulate a total cost evaluation value that is a total of the obtained cost evaluation values for the comfort and the electricity bill for a predetermined period using the calculated electricity daily load curve, the applied-rate-plan group information stored in the memory unit and the obtained control preference information; an individual-consumer control optimizing unit which is adapted to obtain the control-target equipment information from the memory unit, generate for each electrical equipment a plurality of candidate data for electrical equipment control information having the control contents to be changed and set, such as a control time and a control target value of the electrical equipment, instruct the control simulating unit to perform simulation on the plurality of generated candidate data, select the control contents to the electrical equipment so that the total cost evaluation value becomes minimum among the plurality of candidate data as a result of the simulation, and generate electrical equipment control information based on the selected control contents; and a transmitting unit that is adapted to transmit the generated electrical equipment control information to the power operating devices. a memory unit that is adapted to store a predetermined energy consumption model for predicting an electricity daily load curve indicating an electrical power consumption per predetermined time using parameters which are control-target equipment information of the power operating devices, applied-rate-plan group information indicating an electricity unit meter-charge applied to the power operating devices and an applied period of the electricity unit meter-charge, and control contents to the electrical equipment and a forecasting value relating to a future weather condition; an information obtaining unit that is adapted to obtain control preference information including cost evaluation values which are barometers indicating a compatibility of restraint conditions to a comfort and an electricity bill for each consumer, the comfort and the electricity bill being set and input by the power operating devices; a control simulating unit which is adapted to obtain the energy consumption model from the memory unit in order to calculate the electricity daily load curve, and which is adapted to simulate a total cost evaluation value that is a total of the obtained cost evaluation values for the comfort and the electricity bill for a predetermined period using the calculated electricity daily load curve, the applied-rate-plan group information stored in the memory unit and the obtained control preference information; an individual-consumer control optimizing unit which is adapted to obtain the control-target equipment information from the memory unit, generate for each electrical equipment a plurality of candidate data for electrical equipment control information having the control contents to be changed and set, such as a control time and a control target value of the electrical equipment, instruct the control simulating unit to perform simulation on the plurality of generated candidate data, select the control contents to the electrical equipment so that the total cost evaluation value becomes minimum among the plurality of candidate data as a result of the simulation, and generate electrical equipment control information based on the selected control contents; and a transmitting unit that is adapted to transmit the generated electrical equipment control information to the power operating devices.