Abstract: The operating principle,the performance and the application of a micromanipulator system(MMS) setup in a scanning electron microscope(SEM)is introduced in this paper.The movement precision of the MMS in clock-unclockwise rotation(X-axis),up-down rotation(Y-axis),and retreat-forward linearity(Z- axis)is 5,3.5 and 0.25 nm,respectively.The MMS with nano-precision in the movement and the position was used to in-situ manipulate and dynamically observe nano-sized materials,including BiVO₄ crystals, diatomites,opals and ZnO nanowires.The setup can manipulate the samples,which possess the quality within nano kilogram and the size from several hundred nanometers to several micrometers.The SEM-MMS system is a novel means for in-situ analysis of nano-sized materials.