A construction machine includes: a work device; an operation device which receives a manipulation; a hydraulic unit including a hydraulic motor; an electric unit including an electric motor and an energy storage unit; a control device which makes the electric power of the energy storage unit assist the hydraulic unit upon the manipulation for the drive side, and makes the electric motor generate regenerative electric power unit upon the manipulation for the regeneration side; and a power-discharge command unit which issues a discharge command for the energy storage unit. Upon receiving the discharge command, the control device operates the electric motor to lower a voltage of the energy storage unit upon the manipulation for the drive side, and makes only the hydraulic unit decelerate or stop the work device upon the manipulation for the regeneration side.