The manufacturing of optics is an important field of technology and will serve keymarkets today and in the future. Nevertheless, the application of complex optical elements is much restricted today despite of their outstanding functional advantages. Furthermore, the replication of structured optical components requires high precision molds. Diamond machining processes like diamond milling and cutting as well as abrasive polishing are appropriate micro-structuring techniques for optical molds. The combination of these key machining technologies with replication techniques within closed process chains will open the possibility to produce high precision complex optical elements as mass-product articles for many optical applications. Important machining techniques for optical mold manufacture are presented and discussed.