In an output control of a hybrid-type engine generator equipped with a load output demand detecting unit, a load output demand increase/decrease determination unit and an output control unit, a configuration is adopted whereby load output demand from (output required by) the load is detected, increase/decrease of the detected load output demand is determined, discharge power from the battery is added to generated power output of the engine generator unit when detected load output demand is determined to be increasing, and output of the engine generator unit is controlled so as to use some generated power output of the engine generator unit as charge power of the battery when detected load output demand is determined to be decreasing.