A thermal flow meter is provided that can accurately correct zero point and span errors, which change depending on an ambient temperature, independently of a fluid type. The thermal flow meter includes: a flow path through which measuring target fluid flows; an upstream side electrical resistive element provided on the upstream side of the flow path; a downstream side electrical resistive element provided on the downstream side of the flow path; and a flow rate calculation part that calculates a flow rate of the measuring target fluid on the basis of an upstream side voltage that is a voltage applied to the upstream side electrical resistive element, a downstream side voltage that is a voltage applied to the downstream side electrical resistive element, and the thermal conductivity of the measuring target fluid.