An assembly includes a semiconductor device having surface-connecting terminals, a substrate having surface-connecting pads, and a capacitor having an approximately plate-shaped capacitor main body having a first surface on which the semiconductor device is mounted and a second surface at which the capacitor main body is mounted on the substrate and a plurality of electrically conductive vias penetrating the capacitor main body between the first and second surfaces and connected to the surface-connecting terminals and the surface-connecting pads.