In transmission electron microscopy (TEM), samples must be placed in a high-vacuum environment and withstand intense electron beam bombardment. Since most samples (e.g., biological macromolecules, nanomaterials, thin-film cross-sections) cannot stably exist in a vacuum chamber on their own, EM grids (Electron Microscopy Grids) serve as the critical support structure. They secure the sample, maintain structural stability, and ensure electron beam penetration for imaging. This article systematically introduces the common types, materials, structures, and typical applications of EM grids.































































































