The object is to provide a printed wiring board high in reliability of an interlayer connection even when a conductor bump is miniaturized and a manufacturing method of such printed wiring board. On a conductor plate 1, approximately conical conductor bumps 1a, 1a, . . . are formed, the conductor bumps 1a, 1a, . . . being caused to penetrate through a prepreg 5 to project tip ends of the conductor bumps 1a, 1a, . . . from an opposite side of the prepreg 5. The tip ends of the conductor bumps 1a, 1a, . . . and interconnection patterns 7a and 7b on surfaces of core material 17A, before bonding, are exposed to plasma to activate. The activated tip ends of the conductor bump 1a, 1a, . . . and interconnection patterns 7a and 7b on the surface of the core material are stacked to bond both.