PURPOSE: To bring an abrasive member and a polished surface come into an equi-pressure contact and make this surface polishable in having them equally contacting at a relatively broad area by installing an abrasive layer on the surface of a flexible ring strut consisting of flexible materials.

CONSTITUTION: Almina fine powder 2 is put close to an outer surface of a rubber hollow doughnut 1 via a bonding agent, setting it down to an abrasive member 3. If this abrasive member 3 is contacted to a polished surface, abrasive powder of this abrasive member 3 and the polished surface come into contact with each other at equi-pressure. The hollow doughnut 1 serving as this ring strut is rotated or slidden whereby equi-pressure polishing takes place. The hollow doughnut 1 or this ring strut gets to fit so well and deformed along a form of the polished surface, so even if it is an irregular curved surface, highly accurate polishing is performable.