The present invention relates to a reamer for forming a hole in the bone for implant placement which is specifically structured so that cutting edges (20) which have a linear form that is horizontal to cutting front end portions (10) having a front end are alternately and radially formed at an upper portion of a cutting portion (1) wherein the rear side of the cutting front end portions (10) is formed as a depressed surface (11) which slants downward toward the center of the cutting portion (1) wherein the rear side of the cutting edges (20) is formed as a slanted surface (21) which slants downward toward an outer circumferential surface of the cutting portion (1) wherein bone storage grooves (31) in which residue of the bone (40) that is eliminated is inserted and accumulated are formed between the cutting front end portions (10) and the cutting edges (20) which are alternately formed and an incline angle of side surface slanted edges (30) which are formed on an outer circumference of the cutting front end portions (10) and the cutting edges (20) becomes gradually smaller in the direction of rotation.
