The properties of femtosecond laser and the mechanisms of femtosecond laser micromaching are introduced, the differences to that of long-pulse laser are emphasized. Femtosecond laser produce high intensity and offer precision breakdown threshold with lower laser fluence. The femtosecond laser micromachining has a very limited heat-affected volume. These advantages of femtosecond laser could be applied in precision micromachining of various materials. Femtosecond laser micromaching can have a micron and submicron feature size. Some femtosecond laser micromachining results, including comparison with long-pulse, are discussed, and the widespread application prospect is described.