A construction machine comprising: a hydraulic pump of variable displacement type; a regulator that regulates displacement volume of the hydraulic pump ; a plurality of hydraulic actuators driven by a hydraulic fluid delivered from the hydraulic pump ; a plurality of flow control valves that control supply and discharge of the hydraulic fluid to and from the plurality of hydraulic actuators ; a plurality of operation devices for operating the plurality of flow control valves ; an operation amount sensor that detects each of operation amounts of the plurality of operation devices ; and a controller that controls the regulator according to each of the operation amounts of the plurality of operation devices detected by the operation amount sensor , wherein the controller is configured to compute a first target displacement volume for each of the operation amounts of the plurality of operation devices , characterized in that the controller is configured to compute a second target displacement volume greater than the first target displacement volume for the same operation amount, for each of the operation amounts of the plurality of operation devices , select as a final target displacement volume (Qfin) either smaller one of a sum total value of a plurality of first target displacement volumes (Qs1, Qs2, ..., Qsn) computed for the operation amounts of the plurality of operation devices and a maximum value (Qcmax) of a plurality of second target displacement amounts (Qc1, Qc2, ..., Qcn) computed for the operation amounts of the plurality of operation devices , and control the regulator according to the final target displacement volume (Qfin). a hydraulic pump of variable displacement type; a regulator that regulates displacement volume of the hydraulic pump ; a plurality of hydraulic actuators driven by a hydraulic fluid delivered from the hydraulic pump ; a plurality of flow control valves that control supply and discharge of the hydraulic fluid to and from the plurality of hydraulic actuators ; a plurality of operation devices for operating the plurality of flow control valves ; an operation amount sensor that detects each of operation amounts of the plurality of operation devices ; and a controller that controls the regulator according to each of the operation amounts of the plurality of operation devices detected by the operation amount sensor , wherein the controller is configured to compute a first target displacement volume for each of the operation amounts of the plurality of operation devices , characterized in that the controller is configured to compute a second target displacement volume greater than the first target displacement volume for the same operation amount, for each of the operation amounts of the plurality of operation devices , select as a final target displacement volume (Qfin) either smaller one of a sum total value of a plurality of first target displacement volumes (Qs1, Qs2, ..., Qsn) computed for the operation amounts of the plurality of operation devices and a maximum value (Qcmax) of a plurality of second target displacement amounts (Qc1, Qc2, ..., Qcn) computed for the operation amounts of the plurality of operation devices , and control the regulator according to the final target displacement volume (Qfin). <EOS>