This brain activity feature amount extraction method includes acquiring a combination of a plurality of data items in order of higher effectiveness for discriminating whether a subject is a healthy person or a non-healthy person, among the plurality of data items, on the basis of the index value serving as the index indicating effectiveness or non-effectiveness for discriminating the group of healthy persons and the group of non-healthy persons from each other, and displaying the acquired combination of the plurality of data items in order of higher effectiveness.