PROBLEM TO BE SOLVED: To measure a glucose concentration of a living body with a simple configuration.SOLUTION: A parameter measuring device includes: a first irradiation part 11 for irradiating light of a first wavelength such that an absorbancy of glucose is about a maximal to a living body； a second irradiation part 12 for irradiating light of a second wavelength such that an absorbancy of glucose is smaller than that of water to the living body； a first measuring part 14 for measuring an intensity of transmitted light through the living body when only the first irradiation part 11 irradiates light to the living body； a second measuring part 15 for measuring an intensity of transmitted light through the living body when the first irradiation part 11 and the second irradiation part 12 irradiate light to the living body； and a parameter calculating part 16 for calculating a glucose concentration in the living body on the basis of the intensity of light measured by the first measuring part 14 and the intensity of light measured by the second measuring part 15.
