PURPOSE: To polish better even the recessed portions of an object to be polished by forming a proper number of protrusions on the external surfaces of a lump body made of a proper material.

CONSTITUTION: A proper number of protrusions 2 are provided in the external surfaces of a lump body 1 made of a proper material to construct a protruded abrasive. The form of the lump body 1 is not limited. Also the form of the protrusions 2 is arbitrary. Though the material of the lump body 1 is arbitrary, for example, nylon or a mixture of nylon and carbon fiber may be used. The protruded abrasive of this form can be produced easily as a cold cut pellet using an extruding machine for plasticizing resin. A recessed object with recessed portions is barrel-polished by the protruded abrasive to polish the recessed portions by the protrusions 2 of the protruded abrasive.