It is an object to provide a cutting tool which can perform high-quality, high-efficiency machining of a workpiece such as hardened steel.The cutting tool includes a finishing cutting edge 6 which initially cuts into the workpiece, and superfinishing cutting edges 7 for finishing the workpiece cut by the finishing cutting edge. The superfinishing cutting edges 7 project from the finishing cutting edge by a predetermined amount B in such a direction that the depth of cut of the superfinishing cutting edges increases. Each superfinishing cutting edge includes a burnishing portion 7a having a predetermined width L in the feed direction of the tool, and a wiper portion 7b. The superfinishing cutting edges 7 burnish the finished surface formed by the finishing cutting edge, while removing a affected layer formed by the finishing cutting edge.