A method for manufacturing a transmission electron microscope (TEM) micro-grid is provided. A sheet of carbon nanotube structure comprising a plurality of carbon nanotubes is first provided. Some carbon nanotubes are removed from selected portions of the sheet of carbon nanotube structure to form a plurality of electron transmission portions. Each of the electron transmission portions includes a hole defined in the sheet of carbon nanotube structure and a plurality of residual carbon nanotubes in the hole. The sheet of carbon nanotube structure having the electron transmission portions is cut into pieces to form the TEM micro-grid.