We have successfully developed a process which can fabricate a number of large diamond wafers from single seed crystal. This process, called "Direct Wafer-Making Technology", is a combination of high rate growth process using microwave plasma CVD and subsequent etching process of graphitized ion implanted layer in the seed. Using this process, 10 mm square, self standing, single crystalline CVD diamond wafers can be synthesized. These large diamond wafers will be essential for future electronic devices which utilize excellent properties of diamond as semiconducting material.