Industrial clusters are often formed to make high quality products, but it is not always successful. In this paper, through the comparison of experimental attributes of Silicon Valley in the U.S. and Cremona, the factors for the successful industrial cluster are discussed. By analyzing both successful clusters with Porter’s Diamond model, four presupposition factors (public support, history, volume of global market, thickness of engineers or artisans) and four common conditions (top management, peer-review, critical eyes of consumers, creativity of engineers or artisans) were extracted.