Solar　cell　interfaces,　including　grain　boundaries,　twin　boundaries,　stacking　faults,　and　phase　boundaries,　are　the　main　nonradiative　recombination　and　degradation　sites　and　affect　the　photoelectric　conversion　efficiency　and　stability　of　solar　cells,　making　it　necessary　to　understand　their　fine　structures　and　properties.　Electron　microscopy　has　provided　micrometer/nanometer/atomic-scale　structural　information　for　investigating　the　microstructure　of　materials　to　unravel　the　structure-performance　relationships　of　solar　cells.　Electron　microscopy　and　related　techniques　have　recently　been　used　to　investigate　solar　cell　interfaces,　but　there　has　been　no　systematic　summary　of　this　research.　In　recent　years,　advances　in　technologies　such　as　electron　microscopy　imaging,　electron　spectroscopy,　in　situ　electron　microscopy,　and　detectors　have　greatly　expanded　researchers＇　understanding　of　the　interface　properties　of　solar　cells.　This　Review　covers　the　research　on　the　interfaces　in　perovskite/silicon/CdTe　and　Cu(In,Ga)Se-2　(CIGS)　solar　cells　using　electron　microscopy　and　provides　prospects　for　further　progress.