The invention concerns a machining tool for machining fiber-reinforced materials such as CFRP, glass-fiber-reinforced plastics or plastics reinforced with polyester threads. The machining tool comprises a plurality of flutes (1, 2, 3, 4) which distance lands (5, 6, 7, 8), disposed about a cylinder core segment (9), from each other in the peripheral sense. At least one of the lands (6, 8) is designed as a premachining land (6, 8) and at least one other of the lands (5, 7) is designed as a postmachining land (5, 7), each comprising a peripheral working region extending along, or with a twist and, in the form of a helical segment about, the tool axis. The working region of each premachining land (6, 8) is designed as a peripheral file with a plurality of teeth (10) which are incorporated in a cylinder surface segment-shaped outer surface of the working region, and provided in the working region of each postmachining land (5, 7) is a number of sharp cutting edges (11, 12, 13, 15) extending parallel to or with a twist and in the form of a helical segment about the tool axis. The invention is characterized in that the number of sharp cutting edges (11, 12, 13, 15) on at least one postmachining land (5, 7) comprises a plurality of cutting edges (11, 12) each provided on a peripheral casing groove, the casing grooves being incorporated in a cylinder surface segment-shaped outer face of the working region, parallel to each other and at a pitch relative to the flute (1, 3) leading at least one postmachining land (5, 7).