HYBRID CONSTRUCTION MACHINE WITH ENGINE CONTROLLER

[Problem] To provide a hybrid construction machine which can provide the same operation feeling as an ordinary construction machine that is not hybrid without changing the discharge flow rate of a hydraulic pump even when the rotation speed of an engine is changed according to power absorbed by the hydraulic pump. [Solution] A hybrid construction machine is provided with a variable displacement hydraulic pump 1 which supplies hydraulic oil to a hydraulic actuator, an engine 2 which is provided to be able to drive and rotate the hydraulic pump 1, an electric motor 3 which is provided to be able to drive and rotate the hydraulic pump 1, an engine control dial 4, a controller 4 and an operating lever 5 . The controller changes the rotation speed of the engine 2 to reduce fuel consumption according to power generated by the engine 2, and changes displacement of the hydraulic pump 1 based on the rotation speed of the engine 2, the dial position of the engine control dial 4 and the amount of operation on the operating lever 5.