To hardly generate clogging, reduce grinding resistance, and prolong the life, by dispersedly fixing super abrasive grains while having step differences on the working surface of a tool.

Super abrasive grains 2 are fixedly secured on a base metal 1 by an electrocast metal layer 9, a part having plating 7 is a high step part 3, and a part having no plating 7 is a low step part 4. Difference of heights of the high step part 3 and the low step part 4 is desirable to be 5-30% of the mean grain size of the super abrasive grain 2, and 8-20% is more desirable. Ratio of area of the high step part 3 to the low step part is desirable to be 3/7-7/3, and 4/6-6/4 is more desirable. By the use of this, at first the super abrasive grains 2 of the high step part 3 function for grinding, hence the degree of concentration is low, grinding resistance is small, and clogging is hardly generated. When the super abrasive grains 2 of the high step part is worn off and omitted by the use, the super abrasive grains 2 of the low step part 4 function for grinding, and similar effect is exhibited.