PURPOSE: To manufacture a diamond sintered body for tools having excellent heat resistance, strength and wear resistance by mixing coarse grain of diamond with the specified bonding material, treating by acid after hot pressing under high temperature and pressure and eluding a part of metallic component in the bonding material.

CONSTITUTION: A powder mixture composed of 60W90% diamond coarse grain of ≥3μm grain size especially 5W200μm grain size and the balance a bonding material having the following composition are made. As a bonding material, by capacity, 60W95% ultra fine grain diamond of ≥1μm gain size, ultra fine grain carbide of the 4a, 5a, 6a group in the periodic table, especially 0.1W5% WC or (Mo, W), <10% Fe group metal of Fe, Ni, Co and the like or 0.005W0.15% boron the final sintered body of boride are utilized. The above mentioned powder mixture is hot-pressed by high temperature and pressure after a part of diamond is graphitized. The generated sintered bocy is treated by acid to elute a part of Fe group metals in the bonding material and to manufacture a diamond sintered boxy, which has 1W5% porosity.