METHOD OF CONTROLLING HYBRID WORKING MACHINE

In a hybrid working machine, a hydraulic pump (21) is driven with the output of an engine (30) and the output of a motor generator (34). The input side power (Win) of the hydraulic pump (21) is calculated, and the output of the motor generator (34) is controlled based on the calculated power (Win). This makes it possible to precisely determine the input side power of the hydraulic pump (21) and to control the load of the engine based on the input side power.