A setting method of a flow meter device which measures a compensation coefficient in a case where a fluid is flowed with a flow within a predetermined range, the setting method being characterized by comprising: A) deriving a first function representing as a linear function a relationship between a measurement compensation coefficient which is the measured compensation coefficient and a conversion value which is obtained by converting a set flow which is the flow of the fluid flowed when the compensation coefficient is measured, using a predetermined function; B) setting a reference flow which is an arbitrary flow within the predetermined range and calculating a reference compensation coefficient which is a compensation coefficient corresponding to the reference flow based on the reference flow and the first function; and C) storing the reference flow and the reference compensation coefficient corresponding to the reference flow, wherein the step A) includes: A1) plotting values of the set flow and the measurement compensation coefficient and deriving an approximate curve from the plot values; A2) setting as the predetermined function a function in which the set flow is a parameter, of an arithmetic expression representing the approximate curve derived in step A1); and A3) determining the first function by setting the predetermined function in the arithmetic expression to a variable, wherein the approximate curve is derived using one of a logarithm function, an exponential function, and a high-order function, wherein the step B) includes: B1) setting the reference flow; B2) calculating a first flow which is a value obtained by converting the reference flow, based on the reference flow set in step B1) and the predetermined function; and B3) calculating the reference compensation coefficient based on the first flow calculated in step B2) and the first function, wherein in step B), the reference flow comprises more values than the set flow. A) deriving a first function representing as a linear function a relationship between a measurement compensation coefficient which is the measured compensation coefficient and a conversion value which is obtained by converting a set flow which is the flow of the fluid flowed when the compensation coefficient is measured, using a predetermined function; B) setting a reference flow which is an arbitrary flow within the predetermined range and calculating a reference compensation coefficient which is a compensation coefficient corresponding to the reference flow based on the reference flow and the first function; and C) storing the reference flow and the reference compensation coefficient corresponding to the reference flow, A1) plotting values of the set flow and the measurement compensation coefficient and deriving an approximate curve from the plot values; A2) setting as the predetermined function a function in which the set flow is a parameter, of an arithmetic expression representing the approximate curve derived in step A1); and A3) determining the first function by setting the predetermined function in the arithmetic expression to a variable, wherein the approximate curve is derived using one of a logarithm function, an exponential function, and a high-order function, wherein the step B) includes: B1) setting the reference flow; B2) calculating a first flow which is a value obtained by converting the reference flow, based on the reference flow set in step B1) and the predetermined function; and B3) calculating the reference compensation coefficient based on the first flow calculated in step B2) and the first function, wherein in step B), the reference flow comprises more values than the set flow. B1) setting the reference flow; B2) calculating a first flow which is a value obtained by converting the reference flow, based on the reference flow set in step B1) and the predetermined function; and B3) calculating the reference compensation coefficient based on the first flow calculated in step B2) and the first function, wherein in step B), the reference flow comprises more values than the set flow.