A printed circuit board for mounting electronic parts thereon includes a ground portion formed on the printed circuit board and connected to an outer ground. A plurality of conductive ground layers are stacked so as to interpose an insulation layer therebetween. An upper conductive ground layer includes first and second conductive ground portions. The first and second ground portions are connected by a connecting element. Another conductive ground layer under the upper conductive ground layer is grounded via the first and second ground portions of the upper conductive ground layer via a through hole provided in the ground portion.