In situ transition electron microscopy (TEM) with its high-resolution imaging and analytic capability is playing an essential role in characterization and manipulation of nanoscale devices. This review article focuses on the application of in situ TEM in a wide range of advanced electronic devices for both fundamental physics study and real-time manipulation. These devices include transistors and non-volatile memory consisted of resistive random access memory, phase change memory, and ferroelectric resistive random access memory. We will show how in situ TEM is powerful in examining the structural evolution, change in chemical component, and devices reliability in atomic scale and real time.