A enables surplus power suppression at rated exceed the table control unit, thereby, to receive the surplus electricity, the generator and speed increaser, spindle unit or the like is not necessary to the capacity of higher rated at , to provide an output control apparatus of miniaturization can be achieved wind turbine generator. A is an output control unit 4 interposed between the generator 3 and the table controller 5. Rotational speed of the wind turbine 1, the rotation speed or the output voltage of the generator 3, the output current, and one of the wind speed is input, the rated output power of the table control unit 5 monitors that exceed the rated output Output It comprises excess monitoring means 23. Comprising a generation voltage control means 24 to lower the power generation voltage of the generator 3 and is estimated that in excess of the rated output. .FIELD 1