A machine body controller 70A includes a modification control unit 70Ab for computing a torque modification value based on detected signals from environment sensors 75 to 83, and modifies a maximum absorption torque of a hydraulic pump controlled by a basic control unit 70Aa. An engine controller 70B includes a modification control unit 70Bb for computing an injection modification value based on detected the signals from the environment sensors 75 to 83, and modifies a fuel injection state of a fuel injection device 14 controlled by a basic control unit 70Ba. The controllers 70A, 70B further include computation element altering units 171, 181. A communication controller 70C downloads alteration data obtained from an external terminal 150 to the computation element altering units 171, 181, whereby corresponding computation elements contained in the modification control units 70Ab, 70Bb are altered. As a result, it is possible in any environments to approprately modify the maximum absorption torque of the hydraulic pump and the fuel injection state of the injection device, and to sufficiently develop the performance of a construction machine.