Provided is an apparatus for estimating bio-information which estimates bio-information from a user. The apparatus for estimating bio-information according to an embodiment of the present disclosure includes: a spectrometer configured to obtain, absorbance from a user; a physiological information obtainer configured to obtain metabolic and physiological information including a concentration of carbon dioxide (CO2); and a processor configured to estimate bio-information based on the absorbance and the metabolic, and physiological information by using a predictive model corresponding to the obtained metabolic and physiological information.