An energy management device according to an embodiment of the present invention comprises: a communication unit for receiving energy information of a system to which the energy management device belongs; a display unit for displaying any one energy information icon on the basis of the received energy information; and a control unit for displaying at least one energy information icon corresponding to a lower level of the energy information icon upon receiving a command to select an expansion icon corresponding to the energy information icon, and connecting the energy information icon having the selected expansion icon and the energy information icon corresponding to the lower level to energy nodes having different thickness according to the amount of energy.