To provide a manufacturing method of a semiconductor device making improved the reliability of a semiconductor device manufactured by cutting a semiconductor wafer subjected to plating.

After the electrical characteristic of a semiconductor wafer are evaluated by using a TEG formed in a scribe region of the semiconductor wafer (Step S11), an insulating mask layer which masks the TEG is formed (Step S12). After the semiconductor wafer is subjected to electroless plating with the mask layer formed (Step S13), the semiconductor wafer is diced along the scribe region (Step S14). Consequently, a plated film is not formed in the TEG in electroless plating and conductive chips in dicing are reduced. Accordingly, a conductive foreign matter is restrained from adhering to the surface of a semiconductor chip, and thereby reliability of the semiconductor chip, s well as, eventually the semiconductor device wherein the semiconductor chip is mounted are improved.