Disclosed herein is a digital filter circuit for producing a noise reduction signal for reducing noise based on a noise signal outputted from a microphone which collects the noise, including: an analog/digital conversion section； a first digital filter section； an arithmetic operation processing section； a second digital filter section； and a digital/analog conversion section. The first digital filter section and/or the second digital filter section are configured such that a predetermined attenuation amount is obtained within a predetermined range in the proximity of a sampling frequency around the sampling frequency.
