Knowledge-based Service Industry is an industry that creates added value through the production, processing, and use of knowledge. Comparing to other service industries, it is innovation-oriented business endeavors having the characteristics that exert the great influences on other fields. Meanwhile, however, research efforts thereof are yet insignificant. In this study, we analyzed the innovation performance of architectural design office which creates knowledge services, having raised the necessity of innovation of the design office. The innovation performance were classified according to the extent of efficiency of the architectural design office making use of DEA-Tier analysis, and, for those architectural design offices that showed significant differences in efficiency, we presented the case studies of the firms that were substantial benchmarking targets from short, medium, and long-term perspectives.