An energy conservation diagnosis system manages electrical device K which consumes electricity to operate based on control schedule information, and comprises acquiring unit 14a, rule information generation unit 14b, operating determination unit 14c and display unit 12. Acquiring unit acquires operating information obtained by means of relating an operating condition of electrical device to a clock time. Rule information generation unit generates rule information by means of relating a rule on use of electrical device to a clock time, based on one or more predetermined time slots depending on a benefit of electricity consumed by electrical device. Operating determination unit acquires control schedule information of electrical device, and generates an image data by means of superimposing acquired control schedule information and rule information onto operating information so that each clock time is fitted to a clock time of operating information. Display unit displays the image data.