A power supply noise reduction circuit and a power supply noise reduction method for reducing power supply noise at any frequency, includes forcing a power supply noise to resonate to the resonance frequency of a parallel resonance circuit, including an inductor and a capacitor to set the frequency of the noise equal or close to the resonance frequency of the parallel resonance circuit and, attenuating the noise, set equal or close to the resonance frequency of the parallel resonance circuit, using a low-pass filter including a resistor and a capacitor.