A boring instrument guiding device which is used to guide a boring instrument that forms a pilot hole for embedding a pedicle screw in a vertebral pedicle includes a reference pin 3 which is used as a reference by being inserted into the vertebral arch from the rear to the front of a spine, and an arm 4 which extends sideward from the proximal end side of the reference pin 3, and is characterized in that a plurality of guide holes 12, each of which is opened toward the tip position 3a of the reference pin 3 to guide the boring instrument 2, are formed in the arm 4 in a radial pattern centered at the tip position 3a of the reference pin 3. It is possible to provide a boring instrument guiding device which is capable of more easily and precisely guiding the boring instrument.