PURPOSE: To provide an oval grindstone chip mounting-in type grinding plate easy to mount on a board with an oval grindstone chip to grind a stone or others by improving a mounting structure for the board, a holddown and the oval grindstone chip.

CONSTITUTION: A grindstone chip 15 is inserted into an oval split in a grindstone chip mounting plate 12 from upward. Then, the inclination face 19a of the grindstone chip is inserted along the inclination face 17c. It is stopped in the state that the top of the grinding stone chip 15 is flush with the top of the chip mounting plate 12. In such a state, the top of the grinding stone chip 15 inserted in the chip mounting plate 12 is matched to a rubber packing 13 for a board 11 and layered. Both are fixed together and integrated with a flush screw 21 to form a grindstone chip fitting-in type grinding plate. When one of the grindstone chips 15 is damaged or when the deviation of a whole wear rate is averaged, the flush screw 21 is removed and the intended grindstone chip 15 is pushed out upward for easy replacement.