A decision making support device including: an opinion acquiring module that acquires an expressed opinion from each of a plurality of participants with respect to each of the plurality of selective elements; and a target person determining module that determines, with respect to a given selective element, from which participant an opinion on the selective element is to be elicited when there are a plurality of unexpressed participants who have not yet expressed opinions on the selective element, wherein the target person determining module respectively calculates, when assuming that each of the unexpressed participants has expressed any of expected opinions, assumed group satisfaction that is determined based on contents of decision making and contents of expression of opinions of the plurality of participants, and determines from which participant an opinion on the selective element is to be elicited in consideration of the assumed group satisfaction.