An organic compound analyzer is provided which is capable of highly accurately determining a denaturation feature point on which a minute structural change of an organic compound is reflected. The organic compound analyzer includes an actual measured data storage section, an evaluation criterion vector setting section, a score calculation section, and a change feature point determination section. The actual measured data storage section is configured to store in pairs a plurality of actual measured spectra obtained through measurement of a sample containing an organic compound under a plurality of different external stimulus conditions, and external stimulus conditions under which spectra are respectively measured. The evaluation criterion vector setting section is configured to set a loading that indicates weighting to individual wavenumbers at which the spectra are measured. The score calculation section is configured to calculate a score corresponding to the loading for each of external simulation conditions under which the spectra are measured, on the basis of the loading and the actual measured data. The change feature point determination section is configured to calculate a denaturation temperature of the organic compound on the basis of a change in the score with respect to external stimulus conditions.