Current state of the art of R&D to realize fabrication of diamond wafer is summarized with its motive force for the industrial applications. Among several artificial methods to grow diamond crystals, microwave plasma chemical vapor deposition is the most widely adopted method for electronic and quantum applications. Several trials to improve the growth rate and to enlarge size of the seed crystals were proposed. In addition to the growth technique, its processing technique to dope the impurities for electronics and spintronics applications have been also developed to control the conductivity and sensitivity of the spin-related quantum information. At present, diamond is produced mainly for mechanical application and gemstones. Based on its material constants superior to those of other semiconductor materials, diamond has been interested in the field of the power electronics. On the other hand, use of the nitrogen-vacancy center is recently interested in the field of spintronics applications, because one may be able to use its quantum information under steady state. In addition, its high thermal conductivity is expected to be very useful to avoid heating up of the power devices made of, such as GaN. Realization of these attractive applications require further developments of the growth and processing techniques and clarification of the targets in these applications.