This tool path generating method, which generates a tool path for machining a corner section at which a recess section machined in a workpiece intersects with the outer circumferential surface of the workpiece, includes: a step for calculating a virtual traveling direction, which is a movement direction of a point on the rotational axis line of a rotating tool when the recess section is machined; a step for calculating the position of the corner section from the virtual traveling direction and shape data of the workpiece; and a step for generating a tool path for machining along the calculated position of the corner section.