PURPOSE: To prevent a metal ion shortage with a plating liquid being effectively fed to the vicinity of the face to be plated, by feeding the abrasive grain precipitated at the lower part of a plating tank to the face to be plated of a grindstone base body via the abrasive grain flow pass with the plating liquid blown in from a lead-in port, and reciprocating a nozzle while injecting the plating liquid from the nozzle.

CONSTITUTION: Abrasive grains precipitated at the lower part of a plating tank 10 are fed to the face 20A to be plated of a grindstone base body 20 via an abrasive grains flow pass 15 by the plating liquid M blown in from a lead-in port 12. On the other hand, a metal ion shortage is prevented and also other excessive abrasive grains are blown off with the abrasive grain that the deposition by a metal plating phase is progressed to some extent being left, of the abrasive grains deposited on the face 20A to be plated, as well as the metal ion shortage being prevented, with a plating liquid M being effectively fed to the vicinity of the face 20A to be plated, by reciprocating a nozzle 38 while injecting the plating liquid M from more than one nozzle 38. The distribution density of the abrasive grains in an abrasive grain layer is made uniform and optimum, and a high productivity is obtained, by repeating this motion.