CONSTRUCTION MACHINE

To provide a construction machine that appropriately sets the magnitude of an engine output for each work mode. A construction machine according to the present invention includes: an engine (); a generator-motor () configured to generate electric power by the engine; a hydraulic pump () configured to be driven by the engine and the generator-motor; a hydraulic actuator () that drives and operates a working device () with the power of the hydraulic pump; an electric storage device () for supplying electric power to drive the generator-motor and charging the electric power generated by the generator-motor; a work-mode selecting device () that selects a work mode corresponding to operation of an operator; and an engine-output setting unit () that sets the magnitude of the output of the engine corresponding to the work mode selected by the work-mode selecting device.