Electron beam radiation or plasma treatment of the extracellular substances (ECS) of Drosophila's maggots allowed them to survive in the high vacuum environment of a scanning electron microscope (SEM). The plasma-polymerized nano-film of the ECS acts as a protective layer for the rapid dehydration under the reduced pressure of SEM observation. Artificial coating of polysorbitan monolaurate (Tween-20) allowed organisms without a natural ECS to survive under SEM experiment. The results of grazing-incidence small-angle X-ray scattering (GI-SAXS) experiment indicate that the plasma-irradiated surface of the Tween-20 thin film inhibits water evaporation from the insect body. We have proposed a novel method of “NanoSuit” for the high resolution SEM observation of living specimens.