A power factor correction converter includes an output voltage error amplifier which functions as a proportioning device in a low-frequency range in order to stabilize the output voltage by feedback control and obtains a reference current amplitude value vm by multiplying an error ev between a desired output voltage value Vref and a detected output voltage value vo by a predetermined proportionality factor. A factor element multiplies the reference current amplitude value by a predetermined factor and adds the resulting value to a reference value to obtain a desired output voltage value. The factor element functions as a low-pass filter by changing the desired output voltage value Vref in accordance with the reference current amplitude value vm in a low-frequency range and reducing the factor value in a high-frequency range.