PURPOSE: To obtain always a stable grinding characteristic even if the grinding layer of a grindstone is worn out, by radially directing numerous needle pellets in the direction toward the center of a grindstone base metal with the use of a magnet, and then by filling a bonding agent thereto and calcining thereof so that an ultraabrasive is uniformly distributed.

CONSTITUTION: In a method of manufacturing an ultra-abrasive grindstone having a uniform abrasive distribution, needle pellets 1 are produced at the first step. Each pellet 1 is such that ultra-abrasive particles 4 are bonded, in an equally spaced relation, to a pure iron thin wire 2 having a length corresponding to the thickness of a grinding layer, with the use of a resinoid bond 3. Then, the pellets 1 are embeded at equal piches on a tape-like metal foil as at the second step. Such a metal foil is bonded to the internal peripheral surface of a metal die by means of a bonding agent or the like. Further, magnets are arranged to the periphery of the die and the center part of a grindstone base metal, respectively. In this stage, the base metal and the pellets are calcined after a bonding agent is filled into the die. Accordingly, a stable grinding characteristics may be always obtained.