An object of the present invention is to provide a structure, particularly, a power semiconductor module, which suppresses a bypass flow of a cooling medium and improves cooling efficiency. A structure according to the present invention includes a heat dissipation plate thermally connected to a heating element, and a resin region having a resin material that fixes the heating element and the heat dissipation plate, wherein the heat dissipation plate includes a fin portion including a plurality of fins protruding from a heat dissipation surface of the heat dissipation plate and formed to be exposed from the sealing resin material, and a wall portion formed to protrude from the heat dissipation surface to a same side as the fin and which separates the fin portion and the resin region.