A columnar bump formed of copper etc. is formed on a wiring film of a semiconductor chip through an interconnected film and an adhesive film in a wafer unit by electrolytic plating in which package formation is possible. An oxidation prevention film is formed of such as gold on an upper surface or a part of the upper surface and side surface. A wet prevention film of such as an oxide film is formed on the columnar bump side as needed. If this bump is soldered to the pad on a packaging substrate, solder gets wet in the whole region of the columnar bump upper surface and only a part of the side surface. Stabilized and reliable junction form can be thus formed. Moreover, since the columnar bump does not fuse, the distance between a semiconductor board and a packaging board is not be narrowed by solder.