PURPOSE: To permit a number of thin-edge grindstones having high rigidity and high accuracy to be prepared at one time by immersing a number of base members set onto a base-member installing jig, vertically into a plating liquid containing grinding grains such as diamond and revolving said base members in electric conduction.

CONSTITUTION: A carbon tool steel plate having a thickness of 0.05W0.2mm is worked by the conventional photoetching method so that circular warp or burr is not generated, and about five pieces of base members 3 are installed onto a bed metal installation jig. After the conventional plating foretreatment, the installed base members 3 are set into a plating bath 14 so as to be vertical, and then diamond grinding grains and nickel are codeposited onto the surface of the edge surface and the side surface of the base member 3, and thus a grindstone is formed. Each dispersion in the concentraton degree of diamond and the thickness of this grindstone consisting of five pieces of base members is less, and quality is stable. Therefore, a number of grindstones each of which is thin and has high rigidity can be prepared at one time, and productivity can be improved.