To provide a construction machine capable of notifying an operator or the like of an energy saving state such that an engine thereof stops irrespective of the operator's will or the like. The construction machine wherein its engine is made in an energy saving state when an operator leaves from an operator's seat 13 and no work is performed includes display means 30 for displaying the energy saving state. The construction machine displays the energy saving state by the display means 30 by means of a display lamp 33 that is capable of being recognized from the outside of the machine, and displays the energy saving state by the display means 30 by means of a monitor screen 26 that is provided in an operator's cabin 11 as monitor display.