A multilayer printed wiring board 10 includes: a mounting portion 60 on the top surface of which is mounted a semiconductor element that is electrically connected to a wiring pattern 32, etc.; and a capacitor portion 40 having a high dielectric constant layer 43, formed of ceramic and first and second layer electrodes 41 and 42 that sandwich the high dielectric constant layer 43. One of either of the first and second layer electrodes 41 and 42 is connected to a power supply line of the semiconductor element and the other of either of the first and second layer electrodes 41 and 42 is connected to a ground line. In this multilayer printed wiring board 10, high dielectric constant layer 43 included in the layered capacitor portion 40, which is connected between the power supply line and the ground line, is formed of ceramic. With this structure, the static capacitance of the layered capacitor portion 40 can be high, and an adequate decoupling effect is exhibited even under circumstances in which instantaneous potential drops occur readily.