According to an embodiment, management server includes estimator, scheduler, acquisition unit, monitoring unit, receiver and setting unit. Estimator calculates estimated value of energy demand in building with electric appliance. Scheduler creates schedule of appliance based on estimated value. Acquisition unit acquires actual value of energy demand. Monitoring unit monitors error between estimated value and actual value. Receiver receives DR signal containing information which prompts suppression of energy consumption in a designated period. Setting unit sets threshold. Estimator recalculates estimated value if error is equal or more than threshold. Scheduler reforms schedule based on the recalculated estimated value.