Abstract: The energy management system includes a judging means (103), a usage information means (105), a schedule input means (106), a simulating means (108), a prediction information indicating means (110). The judging means (103) judges whether or not the device was used for each unit time, on the basis of power consumption of the device in a predetermined time period (measurement value). The usage information indicating means (105) indicates whether or not the device was used for each unit time, on the basis of the judgment result of the judging means (103). The schedule input means (106) requires a user to input schedule information which defines operation of the device for each unit time in the predetermined time period. The simulating means (108) calculates power consumption (prediction value) used in the device which operates in accordance with the schedule information input via the schedule input means (106), on the basis of the measurement value.