A voltage converter module is formed by multi-layering a first connecting layer, a first inner wiring layer, a component built-in layer, a second inner wiring layer, a second connecting layer, and a capacitor-mounted layer, and a capacitor built-in layer with resin composite. A connecting terminal formed on a terminal surface of the first connecting layer, the first inner wiring layer, the second inner wiring layer and the capacitor-mounted layer are electrically coupled to each other through via-hole conductors. The second inner wiring layer couples a voltage converter IC to peripheral components, both being incorporated in the component built-in layer. A first capacitor and a second capacitor incorporated in the capacitor built-in layer are mounted to the capacitor-mounted layer. This structure forms a circuit, in which the first capacitor is coupled to the second capacitor, between the voltage converter IC and the grounding.