A calibration curve creation method of creating a calibration curve used to obtain a component amount for a target component contained in a test object, the method comprising:
- (a) acquiring, by executing a computer program being implemented on a computer or a hardware circuit, Q optical spectra obtained through spectrometry using a measurement device on Q first samples each containing N components including the target component, and S evaluation spectra obtained through spectrometry using the measurement device or another measurement device on S second samples in which a component amount for the target component is known, where the Q is an integer of 3 or more, the N is an integer of 1 or more, and the S is an integer of 3 or more;
- (b) extracting, by executing the computer program R subsets from a set of the Q optical spectra, each of the R subsets containing a corresponding subset of the optical spectra of the Q optical spectra, a number of the optical spectra in the respective R subsets being equal to 2 and less than the Q, where the R is an integer of 2 or more;
- (c) determining, by executing the computer program, N component calibration spectra corresponding to the N components by performing independent component analysis in which component amounts for the N components are treated as independent components in each sample on each of the R subsets, and acquiring a total of R×N component calibration spectra;
- (d) obtaining, by executing the computer program, S inner product values by performing an inner product between each of the R×N component calibration spectra and the S evaluation spectra;
- (e) obtaining, by executing the computer program, a correlation degree between a component amount for the target component in the S second samples and the S inner product values with respect to each of the R×N component calibration spectra, and, from among the R×N component calibration spectra, selecting a component calibration spectrum causing the correlation degree to be greatest as a target component calibration spectrum;
- (f) creating, by executing the computer program, as the calibration curve, a single regression formula indicating a relationship between an inner product value obtained through an inner product between the S evaluation spectra and the target component calibration spectrum, and a component amount for the target component contained in the S second samples;
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- (g) displaying the component amount for the target component in the test object on a display.