Apparatus administration system includes control device that controls operation of apparatuses and display device communicable with the control device. In the control device, control unit controls each apparatus in accordance with operation schedule stored in schedule storage unit. Operation history storage unit stores operation history in which past operation states are associated with operated dates and times. In the display device, information acquisition unit acquires the operation schedule and the operation history from the control device. Date and time setting unit specifies past date and time to set as set date and time. Estimation unit estimates operation state at the set date and time through the operation schedule. Extraction unit extracts actual operation state at the set date and time from the operation history. Display unit displays the operation state under schedule control and the actual operation state adjacently.