Which kind of microscope can see the smallest things?

The scanning tunneling microscope (STM) is capable of seeing the smallest structures at the atomic level. It uses a sharp tip that scans the surface of a conductive material, allowing it to visualize individual atoms. Another powerful type is the atomic force microscope (AFM), which can also resolve nanoscale features. Both types of microscopes surpass the capabilities of traditional optical microscopes in terms of resolution.