To identify quickly and simply the blending ratio of a measuring object, without destroying the object to be measured.

This blending ratio identification method of a composite material has a measuring step (S31) of measuring the impedance change in a coil, by drawing the coil excited by an alternating current having an excitation frequency lower or higher than the resonance frequency of the coil itself, close to an object compound material which is an object whose compounding ratio is to be identified; a distance calculation step (S34) of calculating the distance to the origin, from a coordinate wherein the first value determined by dividing the resistance component value by the reactance component value in an impedance change vector, and the second value which is the reactance component are used respectively as X-coordinate value and Y-coordinate value, on the XY-coordinate wherein the X-axis and the Y-axis are used respectively for the resistance component of the impedance and the reactance component; and a compounding ratio identifying step (S35) of identifying the compounding ratio of the object compound material, by collating the distance calculated, beforehand, with a correlation between the distance determined by a step similar to each step and a known blending ratio, relative to a plurality of standard compound materials having known compounding ratios.