DRILL BIT

PROBLEM TO BE SOLVED: To provide a drill bit preventing diamond abrasive grains from peeling off by improving the body shape of a diamond abrasive grain-attaching portion.SOLUTION: The drill bit deposits diamond abrasive grains 5 to the tip of a cylindrical body 2. A portion of the tip of the body 2 is formed to be a retreating surface 2b retreating to the rear in the axial direction with regard to a tip surface, where more diamond abrasive grains 5 are stacked in the retreating surface 2b than the tip surface to form multiple layers. A key groove extending to the rear in the axial direction from the tip portion is formed on the body 2. The positional relation is such that part or all of the opening surface to the tip of the key groove is included in the retreating surface 2b.