Proposed is a configuration of a heat generating element that can maintain heat radiation performance when the configuration of a heat conductive member has been changed. This proposal device comprises: a reference performance calculation unit for calculating heat radiation performance based on a reference model indicating a configuration of a semiconductor device in which a heat generating element is provided to a heat conductive member formed from a plurality of layers; a comparative performance calculation unit for calculating heat radiation performance based on a comparative model obtained by changing the configuration concerning the heat conductive member in the reference model; a proposal configuration generation unit for generating a proposal model obtained by changing the configuration concerning the heat generating element in the comparative model such that heat radiation performance based on the comparative model is equal to heat radiation performance based on the reference model; and a result output unit for outputting information based on the proposal model.