This paper describes the concept and mechanism of ion beam technologies and
the ion beam processing apparatus. Machining characteristics such as the d
ependence of the sputtering yield or specific machining rate on the ion inc
idence angle and the ion energy, and the problems and advantages of ion bea
m technologies are discussed. Finally, applications of ion beam technologie
s to the finishing or sharpening of diamond tools and the engraving of fine
patterns into diamond chips are described.