A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 1×10−12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.