An energy management device comprising: a communication unit configured to receive energy information of a system to which the energy management device belongs; a controller configured to acquire an energy position where energy is consumed or supplied and an amount of energy consumed or supplied at each energy position based on the received energy information; and a display unit configured to display at least one energy information icon based on the acquired energy position and the amount of energy; wherein the controller is further configured to display at least one second energy information icon corresponding to a low level of a first energy information icon when a command for selecting an expansion icon included in the first energy information icon is received and to connect the first energy information icon with the second energy information icon through an energy node , and wherein the controller is further configured to display a thickness of the energy node differently according to the amount of energy corresponding to the second energy information icon , wherein the controller is further configured to: display a problem occurrence list indicating an energy related problem occurring in the system to which the energy management device belongs, when a command for selecting any one item from the problem occurrence list is received, acquire a problem occurrence position corresponding to the selected item, and display an energy information icon of a highest level, an energy information icon corresponding to the acquired problem occurrence position and at least one energy information icon included between the highest level and the problem occurrence position. a communication unit configured to receive energy information of a system to which the energy management device belongs; a controller configured to acquire an energy position where energy is consumed or supplied and an amount of energy consumed or supplied at each energy position based on the received energy information; and a display unit configured to display at least one energy information icon based on the acquired energy position and the amount of energy; wherein the controller is further configured to display at least one second energy information icon corresponding to a low level of a first energy information icon when a command for selecting an expansion icon included in the first energy information icon is received and to connect the first energy information icon with the second energy information icon through an energy node , and wherein the controller is further configured to display a thickness of the energy node differently according to the amount of energy corresponding to the second energy information icon , wherein the controller is further configured to: display a problem occurrence list indicating an energy related problem occurring in the system to which the energy management device belongs, when a command for selecting any one item from the problem occurrence list is received, acquire a problem occurrence position corresponding to the selected item, and display an energy information icon of a highest level, an energy information icon corresponding to the acquired problem occurrence position and at least one energy information icon included between the highest level and the problem occurrence position. display a problem occurrence list indicating an energy related problem occurring in the system to which the energy management device belongs, when a command for selecting any one item from the problem occurrence list is received, acquire a problem occurrence position corresponding to the selected item, and display an energy information icon of a highest level, an energy information icon corresponding to the acquired problem occurrence position and at least one energy information icon included between the highest level and the problem occurrence position. <EOS>