A thermal-type flow meter that is configured to output an output signal (Vfo), comprising: a signal generator that generates a periodic signal (Vi) indicating the flow rate using a frequency; a shunt circuit that is configured by a plurality of switching elements (Tr1, Tr2, Tr3) connected in parallel, and outputs the output signal (Vfo) corresponding to the periodic signal (Vi); and a delay circuit that delays an operation timing of each switching element (Tr1, Tr2, Tr3) such that the respective switching elements (Tr1, Tr2, Tr3) are turned on at different phases of the periodic signal (Vi), wherein the shunt circuit is configured to lower a signal level of the output signal (Vfo) from a high level in a stepwise shape whenever each switching element (Tr1, Tr2, Tr3) is turned on, and to make the signal level of the output signal (Vfo) fall to a low level when all the switching elements (Tr1, Tr2, Tr3) are turned on, and wherein the delay circuit is adapted to change the delayed time duration (τ1, τ2, τ3) to be shortened as the frequency of the periodic signal (Vi) is increased, and is adapted to change the delayed time duration (τ1, τ2, τ3) to be lengthened as the frequency of the periodic signal (Vi) is decreased wherein the delay circuit is configured by a voltage-dividing circuit that divides a voltage applied to a gate terminal of each switching element (Tr1, Tr2, Tr3) to be different values for each switching element (Tr1, Tr2, Tr3), or wherein the delay circuit is configured by a calculation circuit that calculates the delayed time duration (τ1, τ2, τ3) according to a period of the periodic signal (Vi) and drives the switching element (Tr1, Tr2, Tr3) according to the time duration, wherein the delay circuit is adapted to adjust the delayed time duration (τ1, τ2, τ3) such that the delayed time duration between any switching elements (Tr1, Tr2, Tr3) becomes different from the delayed time duration between other switching elements (Tr1, Tr2, Tr3). a signal generator that generates a periodic signal (Vi) indicating the flow rate using a frequency; a shunt circuit that is configured by a plurality of switching elements (Tr1, Tr2, Tr3) connected in parallel, and outputs the output signal (Vfo) corresponding to the periodic signal (Vi); and a delay circuit that delays an operation timing of each switching element (Tr1, Tr2, Tr3) such that the respective switching elements (Tr1, Tr2, Tr3) are turned on at different phases of the periodic signal (Vi), wherein the shunt circuit is configured to lower a signal level of the output signal (Vfo) from a high level in a stepwise shape whenever each switching element (Tr1, Tr2, Tr3) is turned on, and to make the signal level of the output signal (Vfo) fall to a low level when all the switching elements (Tr1, Tr2, Tr3) are turned on, and wherein the delay circuit is adapted to change the delayed time duration (τ1, τ2, τ3) to be shortened as the frequency of the periodic signal (Vi) is increased, and is adapted to change the delayed time duration (τ1, τ2, τ3) to be lengthened as the frequency of the periodic signal (Vi) is decreased wherein the delay circuit is configured by a voltage-dividing circuit that divides a voltage applied to a gate terminal of each switching element (Tr1, Tr2, Tr3) to be different values for each switching element (Tr1, Tr2, Tr3), or wherein the delay circuit is configured by a calculation circuit that calculates the delayed time duration (τ1, τ2, τ3) according to a period of the periodic signal (Vi) and drives the switching element (Tr1, Tr2, Tr3) according to the time duration, wherein the delay circuit is adapted to adjust the delayed time duration (τ1, τ2, τ3) such that the delayed time duration between any switching elements (Tr1, Tr2, Tr3) becomes different from the delayed time duration between other switching elements (Tr1, Tr2, Tr3).