Bulk silicon micromachining and surface micromachining are both developed from the evolution of microelectronics fabricating technologies, and relevant theoretical basis, technical measures, equipment conditions can be learned from the semiconductor process and even directly used. However, there are limitations to these successor technologies, which are mainly characterized in the low geometric depth to width ratio of microdevices or microstructures and limited material options to silicon. As an important part of micromachining, the micromachining technology of non-silicon materials has also been developed rapidly. This chapter mainly introduces two kinds of metal micromachining technologies, namely LIGA and quasi-LIGA.