A generated power output measuring apparatus includes a load unit connected to a connecting wire between a power generator using natural energy and a power conditioner configured to supply electric power of the power generator to an external load, the load unit being configured to draw a current from the power generator, a measuring unit configured to measure a voltage and current of the power generator via the load unit, and a control unit configured to increase the current flowing through the load unit and cause the measuring unit to make a measurement when the voltage measured by the measuring unit is in a range of operating voltage of the power conditioner.