An object of the present invention is to provide a capacitor-incorporated wiring substrate in which connection reliability can be improved through ensuring of a path for supply of electric potential even upon occurrence of a faulty connection in a via-conductor group. In a capacitor-incorporated wiring substrate of the present invention, a capacitor 50 is accommodated in a core 11, and a first and a second buildup layers 12 and 13 are formed on the upper and lower sides, respectively, of the capacitor 50.