A display device of electric power system information comprises a display unit including a display screen; and a screen display control unit for controlling the display unit. The display screen includes a display area that is divided into a plurality of display cells each of which has a mapping function for showing relative positional relations. The display unit includes an electric power system diagram display function unit for displaying an electric system diagram that embodies the state of an electric power system being a monitoring target, a mapping item display function unit for displaying mapping display items in the background of the electric power system diagram using the display cells, and a menu display function for displaying menus and icons, which are used for selecting the mapping display items, on the display screen, and for accepting selection operations to the menus and icons on the display cells on the display screen. The mapping display items represent information of state quantities regarding the state of the electric power system being the monitoring target, and the mapping display items are displayed per display cell with different colors in accordance with the corresponding values of state quantities.