This electron microscope was made by the factory for television electronics in Berlin and dates from 1966. It has a resolution of about one nanometer. Using electron-optical and light-optical post-enlargements, it achieves a total enlargement of a factor of about one million. The first electron microscope was developed in Berlin by Ernst Ruska and built in 1933. He received the Nobel Prize in Physics for this achievement in 1986.
Electron microscopes achieve incomparably higher magnifications than light microscopes because they work with electron beams, which have wavelength 100,000 times smaller than that of visible light. They have become indispensable instruments for anatomical and histological studies. Subcellular structures and viruses can only be made visible with electron microscopes because light microscopes do not achieve the necessary resolution.
You can find more information about the design and function of electron microscopes in the video with this title on the website of the virtual microscope museum.