A blade-pitch-angle control device used for a wind power generator having a plurality of blades (1, 2, 3), the blade-pitch-angle control device comprising: a memory device in which the predetermined parameters that affect the load fluctuation of the blades, azimuth angles, and pitch-angle command values are stored in association with each other; an azimuth-angle detecting device that detects the azimuth angle of each of the blades; a parameter-detecting device that detects the predetermined parameters; a command-value receiving device that receives the pitch-angle command values for each of the blades from the memory device, the pitch-angle command values being selected on the basis of the azimuth angle of each blade detected by the azimuth-angle detecting device and the predetermined parameters detected by the parameter-detecting device; and a pitch-angle-control command-value generating device that generates pitch-angle-control command values for individually controlling the pitch-angle of each blade on the basis of the pitch-angle command values received by the command-value receiving device and a common-pitch-angle command value that is common to each blade, the common-pitch-angle command value being determined by power generator output information of the wind power generator a frequency-component extraction device that extracts a frequency component corresponding to an integral multiple of the number of blades from any one of the power generation output of the wind power generator, the number of revolutions of the power generator, and the number of rotor revolutions; and a calculation device that calculates a pitch-angle for eliminating the load fluctuation of the blades due to the frequency fluctuation on the basis of the extracted frequency-component, wherein the pitch-angle-control command-value generating device causes the pitch-angle calculated by the calculation device to be reflected in the pitch-angle-control command value. a memory device in which the predetermined parameters that affect the load fluctuation of the blades, azimuth angles, and pitch-angle command values are stored in association with each other; an azimuth-angle detecting device that detects the azimuth angle of each of the blades; a parameter-detecting device that detects the predetermined parameters; a command-value receiving device that receives the pitch-angle command values for each of the blades from the memory device, the pitch-angle command values being selected on the basis of the azimuth angle of each blade detected by the azimuth-angle detecting device and the predetermined parameters detected by the parameter-detecting device; and a pitch-angle-control command-value generating device that generates pitch-angle-control command values for individually controlling the pitch-angle of each blade on the basis of the pitch-angle command values received by the command-value receiving device and a common-pitch-angle command value that is common to each blade, the common-pitch-angle command value being determined by power generator output information of the wind power generator a frequency-component extraction device that extracts a frequency component corresponding to an integral multiple of the number of blades from any one of the power generation output of the wind power generator, the number of revolutions of the power generator, and the number of rotor revolutions; and a calculation device that calculates a pitch-angle for eliminating the load fluctuation of the blades due to the frequency fluctuation on the basis of the extracted frequency-component, wherein the pitch-angle-control command-value generating device causes the pitch-angle calculated by the calculation device to be reflected in the pitch-angle-control command value.