MEMS (Micro Electro Mechanical Systems) enables the fabrication of value-added system devices on silicon chips. Micromachining that is an extended integrated circuit technology is used for the fabrication. A rotational gyroscope with an electrostatically levitated ring rotor was developed for inertia sensing. Wafer level packaging enabled MEMS relay for LSI tester. Multi-probe data storage and multicolumn electron beam lithography are realized by array MEMS which take advantages of photolithography and nanostructures such as carbon nanotubes formed in them. Microprobes and microresonators provide high sensitivity and spatial resolution by utilizing nanostructures.