A gas flow meter having a gas flow detection circuit for detecting a current flowing through a resistor installed in a gas passage and a voltage generated across the resistor and outputting a voltage signal representing a gas flow passing through the gas passage; a noise reduction circuit for reducing external noise; and a digital adjusting circuit for digitally adjusting a signal representing the detected gas flow and outputting the adjusted signal; wherein a voltage signal based on the signal adjusted by the digital adjusting circuit is output.