A multilayer printed wiring board comprises insulating layers and conductor layers being stacked alternately on each other. The conductor layers are electrically connected to each other through viaholes formed in the insulating layers. Each of the viaholes is formed to bulge in a direction generally orthogonal to the direction of thickness of the insulating layer. The multilayer printed wiring board is to have electronic components such as a capacitor, IC and the like mounted on the surface layer thereof.