A cutting tool for cutting a honeycomb core has a plurality of spiral blades (3) each of which is formed integrally with a cylindrical body (2) of the cutting tool and has a lead angle ( gamma ) of 60 degrees or more with respect to an axis of the cylindrical body (2). Each of the blades (3) comprises a radial edge (4) with a lip angle ( alpha ) ranging from 1 degree to 20 degrees along the periphery of the cutting tool and a bottom edge (5) with a lip angle ( beta ) ranging from 1 degree to 20 degrees at the bottom of the cutting tool. The bottom edge (5) is curved outward in the revolutional direction of the blade. <IMAGE>
