PROBLEM TO BE SOLVED: To provide a device estimating a biological state of a subject by using a normalized biological measurement feature amount, which suppresses an influence that a state of the subject and the biological measurement feature amount are easily changed on a statistical value for normalization.SOLUTION: The device normalizes a biological measurement feature amount of the subject and determines a biological state of a subject estimated on the basis of the normalized biological measurement feature amount. In setting of a width of a time range of a group of biological measurement feature amounts or a group of measurement data in the past used in calculating a statistical value of the biological measurement feature amount used in normalization, a width of the time range in a time zone where a change of the biological measurement feature amount in the past is large is set to be shorter than a width of the time range in a time zone where a change of the biological measurement feature amount in the past is small.SELECTED DRAWING: Figure 3
