To provide a construction machine capable of enhancing its operability in combined boom hoisting and revolving operation while preventing a delay in increasing the hoisting speed of a boom.

The construction machine includes an engine, first and second pumps connected to the engine and adapted to be operated by the output torque of the engine, a revolution actuator to be driven by oil discharged from the first pump, a boom cylinder to be driven by oil discharged from at least the second pump, means for detecting the operation amount of an operation member which operates the boom, and a controller. The controller changes at least one of a discharged oil amount from the first pump and a discharged oil amount from the second pump so that the discharged oil amount from the second pump is a predetermined amount relatively greater than the discharged oil amount from the first pump, when detecting boom hoisting operation.