Abstract: A multilayer printed wiring board has such a structure that conductor circuit patterns are formed on a core substrate through interlaminar resin insulating layers and through-holes are formed in the core substrate and a filler is filled in the through-hole. The interlaminar resin insulating layer formed on the substrate is flat and the same kind of roughened layer is formed on the conductor circuit pattern on the substrate over a full surface including a side surface thereof. A cover plated layer is formed just above the through-hole, and the roughened layers are formed on the conductor layer and the conductor circuit pattern located at the same level as the conductor layer over a full surface including side surfaces thereof, and the interlaminar resin insulating layer is formed so as to cover the surfaces of these roughened layers and filled in recess portions between the conductors and flattened on its surface.