Carbon-fiber-reinforced plastics (CFRP) are known as a difficult-to-cut material. We propose the use of a flexible circular saw in a novel machining process for CFRP plate cutting. Unlike a typical circular saw, it can cut curved lines by deflecting the saw body into bowl-like-shape to fit a target curved line. In this paper, we conducted a cutting test on CFRP plates using the flexible circular saw to evaluate its machining characteristics. As a result, the flexible circular saw showed excellent cutting properties compared with endmill cutting. Moreover, it was shown that the flexible circular saw could cut CFRP plates at a high feed rate of more than 3000 mm/min.