A biological state-evaluating apparatus evaluates the biological state to be evaluated, based on generated evaluation function and the previously acquired metabolite concentration data to be evaluated. In the apparatus, a candidate evaluation function-generating unit generates a candidate evaluation function that is a candidate of the evaluation function from the biological state information according to a particular function-generating method. A candidate evaluation function-verifying unit verifies the candidate evaluation function prepared according to a particular verification method. A variable-selecting unit selects the combination of the metabolite concentration data contained in the biological state information to be used in preparing the candidate evaluation function by selecting a variable of the candidate evaluation function from the verification results according to a particular variable selection method. The apparatus generates the evaluation function by selecting a candidate evaluation function to be used as the evaluation function among the candidate evaluation functions based on the verification results accumulated by repeated execution of those units.