A guide jig for guiding a cutting burr attached to a handpiece when forming an implant cavity at an implantation position of an implant, the guide jig comprising: an elongated handle section; a pole section that supports an end side of the handle section; and a guide section that guides the cutting burr, the guide section being providednext to the pole section on the end side of the handle section, wherein: the guide section is provided at one of the back side of the pole section, the diagonally back side of the pole section, the right side and the left side of the pole section, as seen from the handle section side; wherein the guide section is provided in parallel with the pole section as seen from the handle section side, so that the orientation and position of the guide section are adjustable by moving the handle section with the abutting section as a fulcrum, and wherein the pole section is formed into a columnar shape and is fixed to the end of the handle section in an upright position, at least one of the pole section and the guide section protrudes from the end side of the handle section in a direction opposite to a direction of cutting by the cutting burr, further wherein the pole section comprises an abutting section formed on one end of the pole section, the abutting section being tapered such that a diameter of the abutting section decreases in size in the cutting direction. an elongated handle section; a pole section that supports an end side of the handle section; and a guide section that guides the cutting burr, the guide section being providednext to the pole section on the end side of the handle section, wherein: the guide section is provided at one of the back side of the pole section, the diagonally back side of the pole section, the right side and the left side of the pole section, as seen from the handle section side; wherein the guide section is provided in parallel with the pole section as seen from the handle section side, so that the orientation and position of the guide section are adjustable by moving the handle section with the abutting section as a fulcrum, and wherein the pole section is formed into a columnar shape and is fixed to the end of the handle section in an upright position, at least one of the pole section and the guide section protrudes from the end side of the handle section in a direction opposite to a direction of cutting by the cutting burr, further wherein the pole section comprises an abutting section formed on one end of the pole section, the abutting section being tapered such that a diameter of the abutting section decreases in size in the cutting direction. the guide section is provided at one of the back side of the pole section, the diagonally back side of the pole section, the right side and the left side of the pole section, as seen from the handle section side; wherein the guide section is provided in parallel with the pole section as seen from the handle section side, so that the orientation and position of the guide section are adjustable by moving the handle section with the abutting section as a fulcrum, and wherein the pole section is formed into a columnar shape and is fixed to the end of the handle section in an upright position, at least one of the pole section and the guide section protrudes from the end side of the handle section in a direction opposite to a direction of cutting by the cutting burr, further wherein the pole section comprises an abutting section formed on one end of the pole section, the abutting section being tapered such that a diameter of the abutting section decreases in size in the cutting direction.