A method for measuring a scattering-absorption body which is a method for measuring, non-invasively, information relating to an amount of a substance to be measured at a region to be measured of a scattering-absorption body that contains the region to be measured and an intervening tissue that is present between the region to be measured and a surface (Ba) of the scattering-absorption body, the method comprising: a light incidence step of causing pulsed light of a predetermined wavelength that is absorbed by the substance to be measured to be incident, through a light incident position that is set on the surface (Ba) of the scattering-absorption body; a light detection step of obtaining a light detection signal by detecting the light of the predetermined wavelength that propagates through the interior of the scattering-absorption body, at a light detecting position that is set on the surface (Ba) of the scattering-absorption body; a signal processing step of acquiring a temporal profile of light intensity of the detected light, on the basis of the light detection signal; and a calculation step of calculating, on the basis of the temporal profile, a mean optical path length L of the light of the predetermined wavelength in the interior of the scattering-absorption body, and the information relating to the amount of the substance to be measured at the region to be measured, the calculating step further comprising calculating a measurement sensitivity S based upon the expression S = L − 2 × A × LA L where: L is the mean optical path length calculated on the basis of the temporal profile; A is the thickness of the intervening tissue obtained on the basis of a correlation, acquired beforehand, between the mean optical path length L and the thickness A of the intervening tissue; and LA is the optical path length per unit thickness of the intervening tissue obtained from a correlation, acquired beforehand, between the thickness A of the intervening tissue and a pre-correction variation amount ΔX obtained in the case where only the concentration of the substance to be measured is varied; the calculating step further comprising a correction step of correcting the pre-correction variation amount ΔX calculated on the basis of the temporal profile using the measurement sensitivity S so as to obtain a variation amount of the substance to be measured ΔX B1 at the region to be measured in a case where there is varied only the concentration of the substance to be measured, in accordance with the expression: ΔX = SΔ X B 1. a light incidence step of causing pulsed light of a predetermined wavelength that is absorbed by the substance to be measured to be incident, through a light incident position that is set on the surface (Ba) of the scattering-absorption body; a light detection step of obtaining a light detection signal by detecting the light of the predetermined wavelength that propagates through the interior of the scattering-absorption body, at a light detecting position that is set on the surface (Ba) of the scattering-absorption body; a signal processing step of acquiring a temporal profile of light intensity of the detected light, on the basis of the light detection signal; and a calculation step of calculating, on the basis of the temporal profile, a mean optical path length L of the light of the predetermined wavelength in the interior of the scattering-absorption body, and the information relating to the amount of the substance to be measured at the region to be measured, the calculating step further comprising calculating a measurement sensitivity S based upon the expression S = L − 2 × A × LA L where: L is the mean optical path length calculated on the basis of the temporal profile; A is the thickness of the intervening tissue obtained on the basis of a correlation, acquired beforehand, between the mean optical path length L and the thickness A of the intervening tissue; and LA is the optical path length per unit thickness of the intervening tissue obtained from a correlation, acquired beforehand, between the thickness A of the intervening tissue and a pre-correction variation amount ΔX obtained in the case where only the concentration of the substance to be measured is varied; the calculating step further comprising a correction step of correcting the pre-correction variation amount ΔX calculated on the basis of the temporal profile using the measurement sensitivity S so as to obtain a variation amount of the substance to be measured ΔX B1 at the region to be measured in a case where there is varied only the concentration of the substance to be measured, in accordance with the expression: ΔX = SΔ X B 1. L is the mean optical path length calculated on the basis of the temporal profile; A is the thickness of the intervening tissue obtained on the basis of a correlation, acquired beforehand, between the mean optical path length L and the thickness A of the intervening tissue; and LA is the optical path length per unit thickness of the intervening tissue obtained from a correlation, acquired beforehand, between the thickness A of the intervening tissue and a pre-correction variation amount ΔX obtained in the case where only the concentration of the substance to be measured is varied; the calculating step further comprising a correction step of correcting the pre-correction variation amount ΔX calculated on the basis of the temporal profile using the measurement sensitivity S so as to obtain a variation amount of the substance to be measured ΔX B1 at the region to be measured in a case where there is varied only the concentration of the substance to be measured, in accordance with the expression: ΔX = SΔ X B 1.