A construction machine comprising: a hydraulic pump; a regulator that adjusts a delivery flow rate of the hydraulic pump; a plurality of hydraulic actuators (4a, 5a, 6a); a plurality of directional control valves (8a1, 8a3, 8a5) that adjust a flow rate of a hydraulic fluid that is delivered from the hydraulic pump and is distributed to the plurality of hydraulic actuators (4a, 5a, 6a); an operation device for operating the plurality of hydraulic actuators (4a, 5a, 6a); and a controller configured to decide a target flow rate that is a target value of an inflow flow rate of each of the plurality of hydraulic actuators (4a, 5a, 6a) on a basis of an operation signal inputted from the operation device and control the regulator and the plurality of directional control valves (8al, 8a3, 8a5) according to the respective target flow rates of the plurality of hydraulic actuators (4a, 5a, 6a), wherein the construction machine includes velocity sensors (12 - 14) that sense respective operation velocities of the plurality of hydraulic actuators (4a, 5a, 6a), and the controller is configured to calculate the respective inflow flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) on a basis of the respective operation velocities of the plurality of hydraulic actuators (4a, 5a, 6a) sensed by the velocity sensors (12 - 14), determine whether or not combined operation in which two or more hydraulic actuators in the plurality of hydraulic actuators (4a, 5a, 6a) are simultaneously operated is being carried out, on a basis of the operation signal inputted from the operation device, and in a case of determining that the combined operation is being carried out, control the regulator in such a manner that the delivery flow rate of the hydraulic pump becomes larger than a total target flow rate of the plurality of hydraulic actuators (4a, 5a, 6a) and control respective opening amounts of the plurality of directional control valves (8a1, 8a3, 8a5) in such a manner that difference between the respective target flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) and the respective inflow flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) sensed by the velocity sensors (12 - 14) becomes small. a hydraulic pump; a regulator that adjusts a delivery flow rate of the hydraulic pump; a plurality of hydraulic actuators (4a, 5a, 6a); a plurality of directional control valves (8a1, 8a3, 8a5) that adjust a flow rate of a hydraulic fluid that is delivered from the hydraulic pump and is distributed to the plurality of hydraulic actuators (4a, 5a, 6a); an operation device for operating the plurality of hydraulic actuators (4a, 5a, 6a); and a controller configured to decide a target flow rate that is a target value of an inflow flow rate of each of the plurality of hydraulic actuators (4a, 5a, 6a) on a basis of an operation signal inputted from the operation device and control the regulator and the plurality of directional control valves (8al, 8a3, 8a5) according to the respective target flow rates of the plurality of hydraulic actuators (4a, 5a, 6a), wherein the construction machine includes velocity sensors (12 - 14) that sense respective operation velocities of the plurality of hydraulic actuators (4a, 5a, 6a), and the controller is configured to calculate the respective inflow flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) on a basis of the respective operation velocities of the plurality of hydraulic actuators (4a, 5a, 6a) sensed by the velocity sensors (12 - 14), determine whether or not combined operation in which two or more hydraulic actuators in the plurality of hydraulic actuators (4a, 5a, 6a) are simultaneously operated is being carried out, on a basis of the operation signal inputted from the operation device, and in a case of determining that the combined operation is being carried out, control the regulator in such a manner that the delivery flow rate of the hydraulic pump becomes larger than a total target flow rate of the plurality of hydraulic actuators (4a, 5a, 6a) and control respective opening amounts of the plurality of directional control valves (8a1, 8a3, 8a5) in such a manner that difference between the respective target flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) and the respective inflow flow rates of the plurality of hydraulic actuators (4a, 5a, 6a) sensed by the velocity sensors (12 - 14) becomes small.