A Fourier spectroscopic analyzer comprising: a light source; an interferometer configured to emit an interferogram that is interference light to a sample that is an analysis target; a light receiver configured to output a first light reception signal acquired by receiving a wavelength component of a first wavelength band that is a wavelength band of which a spectrum is to be acquired among wavelength components included in transmitted light of the interferogram that has passed through the sample or in reflected light of the interferogram that has been reflected by the sample and a second light reception signal acquired by receiving a wavelength component of a second wavelength band different from the first wavelength band among the wavelength components included in the transmitted light or in the reflected light; and a signal processing device configured to perform a process of eliminating noise superimposed on the wavelength component of the first wavelength band, the noise being caused by changes in the optical characteristics of the sample over time, and a process of acquiring the spectrum of the wavelength component of the first wavelength band by Fourier transform processing, wherein the signal processing device comprises: a noise eliminator configured to perform a process of eliminating the noise superimposed on the first light reception signal by performing a process of subtracting the second light reception signal from the first light reception signal; and a Fourier transformer configured to acquire the spectrum of the wavelength component of the first wavelength band by performing the Fourier transform processing for the first light reception signal from which noise has been eliminated through the process of the noise eliminator. a light source; an interferometer configured to emit an interferogram that is interference light to a sample that is an analysis target; a light receiver configured to output a first light reception signal acquired by receiving a wavelength component of a first wavelength band that is a wavelength band of which a spectrum is to be acquired among wavelength components included in transmitted light of the interferogram that has passed through the sample or in reflected light of the interferogram that has been reflected by the sample and a second light reception signal acquired by receiving a wavelength component of a second wavelength band different from the first wavelength band among the wavelength components included in the transmitted light or in the reflected light; and a signal processing device configured to perform a process of eliminating noise superimposed on the wavelength component of the first wavelength band, the noise being caused by changes in the optical characteristics of the sample over time, and a process of acquiring the spectrum of the wavelength component of the first wavelength band by Fourier transform processing, wherein the signal processing device comprises: a noise eliminator configured to perform a process of eliminating the noise superimposed on the first light reception signal by performing a process of subtracting the second light reception signal from the first light reception signal; and a Fourier transformer configured to acquire the spectrum of the wavelength component of the first wavelength band by performing the Fourier transform processing for the first light reception signal from which noise has been eliminated through the process of the noise eliminator. a light receiver configured to output a first light reception signal acquired by receiving a wavelength component of a first wavelength band that is a wavelength band of which a spectrum is to be acquired among wavelength components included in transmitted light of the interferogram that has passed through the sample or in reflected light of the interferogram that has been reflected by the sample and a second light reception signal acquired by receiving a wavelength component of a second wavelength band different from the first wavelength band among the wavelength components included in the transmitted light or in the reflected light; and a signal processing device configured to perform a process of eliminating noise superimposed on the wavelength component of the first wavelength band, the noise being caused by changes in the optical characteristics of the sample over time, and a process of acquiring the spectrum of the wavelength component of the first wavelength band by Fourier transform processing, wherein the signal processing device comprises: a noise eliminator configured to perform a process of eliminating the noise superimposed on the first light reception signal by performing a process of subtracting the second light reception signal from the first light reception signal; and a Fourier transformer configured to acquire the spectrum of the wavelength component of the first wavelength band by performing the Fourier transform processing for the first light reception signal from which noise has been eliminated through the process of the noise eliminator. a noise eliminator configured to perform a process of eliminating the noise superimposed on the first light reception signal by performing a process of subtracting the second light reception signal from the first light reception signal; and a Fourier transformer configured to acquire the spectrum of the wavelength component of the first wavelength band by performing the Fourier transform processing for the first light reception signal from which noise has been eliminated through the process of the noise eliminator.