This paper presents machining quality and characteristics of circular piercing hole produced by punch press in thermosetting CFRP laminates. First, a hole was produced by using a punch with flat surface at room and elevated temperatures. After the piercing process, damages and burrs on the surfaces and the cutting planes around the hole were microscopically observed. Internal damage such as delamination was then observed using radiography. Second, the quality of the hole was examined through roundness measurement using three coordinate measuring machine. Finally, piercing process mechanism was discussed from antiplane load and displacement diagrams and cutting planes observations of the specimen during the piercing process. It was proved from X-ray radiography and quality evaluation of the hole after the piercing process at elevated temperature that the least amount of delamination was generated although the roundness was low. It was presumed from the piercing process mechanism that the roundness becomes low because the face parallel to fiber direction in the middle layers was preferentially cut.