An analysis apparatus adapted to analyze a measurement target component contained in a sample containing one or more interference components, wherein the sample measurement is performed on the sample and the reference measurement is performed any of before and after every sample measurement or once at appropriate timing, the analysis apparatus comprising: a light source adapted to emit reference light that is light whose wavelength is modulated at a predetermined modulation frequency; a light detector adapted to detect intensity of measurement target light that is light after the reference light has transmitted through the sample, and intensity of the reference light; a first calculation part adapted to calculate an intensity ratio logarithm that is a logarithm of a ratio between the intensity of the measurement target light and the intensity of the reference light; a frequency component extraction part adapted to, from the intensity ratio logarithm, extract mutually different frequency components whose number is equal to or more than a sum of the number of the measurement target component and the number of the interference components, each one of the frequency components corresponding to a frequency n times the modulation frequency, wherein n is an integer equal or more than 1; the analysis apparatus being adapted to store preliminarily obtained independent frequency components obtained by extracting frequency components from intensity ratio logarithms when the measurement target component and the respective interference components are independently present or to store independent intensity ratio logarithms that are intensity ratio logarithms of the measurement target component and the respective interference components per unit concentration, and a second calculation part adapted to calculate the concentration of the measurement target component from which the influence of interference has been removed on a basis of a result of the extraction of the respective frequency components by the frequency component extraction part and the independent frequency components or the independent intensity ratio logarithms. a light source adapted to emit reference light that is light whose wavelength is modulated at a predetermined modulation frequency; a light detector adapted to detect intensity of measurement target light that is light after the reference light has transmitted through the sample, and intensity of the reference light; a first calculation part adapted to calculate an intensity ratio logarithm that is a logarithm of a ratio between the intensity of the measurement target light and the intensity of the reference light; a frequency component extraction part adapted to, from the intensity ratio logarithm, extract mutually different frequency components whose number is equal to or more than a sum of the number of the measurement target component and the number of the interference components, each one of the frequency components corresponding to a frequency n times the modulation frequency, wherein n is an integer equal or more than 1; the analysis apparatus being adapted to store preliminarily obtained independent frequency components obtained by extracting frequency components from intensity ratio logarithms when the measurement target component and the respective interference components are independently present or to store independent intensity ratio logarithms that are intensity ratio logarithms of the measurement target component and the respective interference components per unit concentration, and a second calculation part adapted to calculate the concentration of the measurement target component from which the influence of interference has been removed on a basis of a result of the extraction of the respective frequency components by the frequency component extraction part and the independent frequency components or the independent intensity ratio logarithms. <EOS>