Disclosed herein is a quantitative analyzing method of a copper indium gallium selenide (CIGS) film, the method including: obtaining spectra by irradiating a laser on the plurality of CIGS films having different component compositions, selecting a first spectral line and a second spectral line among the spectra of target elements to be analyzed and obtaining a correlation plot between a measured intensity of the first spectral line and a measured intensity of the second spectral line, correcting the measured intensity of the first spectral line and the measured intensity of the second spectral line using results obtained by curve fitting the correlation plot, obtaining a linear calibration curve using the corrected intensity of the first spectral line and the corrected intensity of the second spectral line; and comparing the linear calibration curve with LIBS analysis of a target sample to be analyzed.