In nanomaterials and microstructural evolution, electron microscopy has had an important effect on materials investigation. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), Electron Diffraction, Operando Electron Microscopy, and Aberration-Corrected Electron Microscopy offer the investigation on understanding of nanoscale material properties and structure. The present research covers the basics, advantages and disadvantages, and material-related applications of various electron microscopy techniques. TEM is useful for investigating atomic arrangements and imperfections in materials, while SEM offers micro- to nanoscale topographical, morphological, & compositional information. EDS, frequently employed with SEM or TEM, analyzes elements and compounds to determine material compositions. Opando Electron Microscopy allows researchers to observe and assess materials during catalytic reactions and battery charge/discharge cycles. This approach is vital for knowing how dynamic processes influence nanoscale material characteristics and behaviour. Another advanced technique, Aberration-Corrected Electron Microscopy, corrects lens aberrations that interfered with electron microscope resolution. This adjustment enables imaging at sample-limited resolutions, allowing further studies of atomic structures & flaws. These electron microscopy methods significantly improve nanomaterial microstructural evolution understanding. These have enabled extensive study of flaws, transitions between phases, and formation mechanisms, which are essential to producing optimal materials.