We have fabricated a patterned diamond field emitter on a silicon substrate. Fine diamond particles were planted on a silicon wafer using conventional scratch method. A silicon oxide film was deposited on the substrate seeded with diamond powder. An array of holes was patterned on the silicon oxide film using VLSI processing technology. Diamond grains were grown using a microwave plasma-assisted chemical vapor deposition. Because diamond could not grow on the silicon oxide barrier, diamond grains filled only the patterned holes in the silicon oxide film, resulting in an array of diamond tips.