A semiconductor package includes a substrate body made of an insulating material and having a frame shape with a through hole; and a heat-dissipating member made of a metallic material and having a top face serving as an element-mounting surface, the element-mounting surface being positioned in the through hole. A back face of the substrate body and a front face of the heat-dissipating member are joined to each other with a joining agent, the back face being oriented downward, the front face being oriented upward. The substrate body includes a first riser portion extending downward from the back face. The heat-dissipating member includes a second riser portion extending upward from the front face. The joining agent is placed in a space enclosed by the back face, the first riser portion, the front face, and the second riser portion.