To provide a prepared hole correcting tool that can straightly correct even a prepared hole distorted in cutting stock made of a high-hardness material.

The prepared hole correcting tool for correcting a prepared hole 2 cut in advance through cutting stock 1 has a plurality of cutting edges 13 of a given width on the tip periphery of a cylindrical tool body 10, and chip pockets 12 inclined from the center to the periphery of the tool body forward of the respective cutting edges in the direction of tool body rotation. An angle θ1 formed between a plane perpendicular to the center axis of the tool body and a bottom 12a of each inclined chip pocket is set smaller than an angle θ2 formed between a plane perpendicular to the center axis of the tool body and each cutting edge.