To improve cut surface accuracy by suppressing heat generation caused by contact with a material to be cut during cutting, and by preventing distortion and vibration of a baseplate, in a rotary disk cutter having an abrasive grain layer where super abrasive grains, e.g. diamond abrasive grains, CBN abrasive grains, or the like, are electrodeposited on the outer periphery and the side surfaces of the baseplate.

On the peripheral part 13 including the peripheral surface and the adjacent edge part of the baseplate 10, abrasive grains D are densely fixed so that most of the abrasive grains D come in contact with each other. In the intermediate area 14 between the peripheral part 13 and a tightening part 12, groups each containing three abrasive grains D or less are uniformly arranged at intervals so that he abrasive grains are arranged and fixed in proportions of 20-60% against the number of abrasive grains when densely arranged in the same area.