In these few years, telecommunication appliances, for example cellular mobile telephone and mobile computer, have been becoming smaller and lighter. In addition they have been equipped with higher performances. Stepping with that progress, the technologies about integrated circuits, electrical components, battery and display devices that are used in those equipment mentioned before have been developing successfully. In the field of multi-layer printed wiring board, many efforts have been made to drill smaller size via holes in order to minimize the size of wiring pattern. Especially laser micro drilling technology that has been expected to be able to overcome the conventional mechanical drilling technology has been spread rapidly into the factory mainly in Japanese market since 1996. As a result, the typical size of the via hole diameter has become 100 to 200 micrometer from 300-400 micrometer and the structure of multi-layer has been changed from through-hole structure to inner via hold structure. Laser micro hole drilling technology nowadays including the ALIVH, which is the name of the printed wiring board that Matsushita has developed, and the survey of the next generation laser drilling technology will be presented.