HYBRID CONSTRUCTION MACHINE

The hybrid construction machine includes an engine (11), an electric motor/generator (14), a hydraulic pump unit (17), an electricity storage device (16), an inverter (15), a temperature regulator (16D or 16E), and a hybrid control unit (22). The hybrid control unit (22) executes at least one of first control for controlling a warming-up battery temperature regulator (16D) so that it increases a temperature of the electricity storage device (16), second control for controlling the inverter (15) so that it reduces the power output from the inverter (15), and third control for controlling a pump capacity control unit (21) so that it reduces the flow rate of a hydraulic fluid delivered from the hydraulic pump unit (17), according to a charge/discharge history of the electricity storage device (16).