To provide a device for evaluating autonomic nerve functions and a stress level for enabling a person without a sufficient knowledge to evaluate "a type of autonomic nerve functions" accurately in a short time and to evaluate "a stress level".

The device for evaluating autonomic nerve functions and a stress level is equipped with an iris diameter and pupil diameter operating means 104 for acquiring values on a ratio of a pupil diameter to an iris diameter in a time-series manner and an autonomic nerve functions/stress level operating means 105 for acquiring values on autonomic nerve functions or/and a stress level from the value which relates to the ratio of the pupil diameter to the iris diameter and is acquired in a time-series manner. The means 105 acquires values on a plurality of prescribed parameters from the value which relates to the ratio of the pupil diameter to the iris diameter and is acquired in a time-series manner, acquires the corresponding plurality of weighting values, and acquires a value on the autonomic nerve functions or/and a value on a stress level corresponding to the total value of the weighting values acquired by prescribed operation.