Copyright © 2007 Dorling Kindersley
Some objects are so small that our eyes cannot see them. We cannot see atoms or molecules, or the cells of our bodies, or viruses that carry disease. A microscope uses lenses to make tiny things appear bigger so we can see them clearly. There are two main kinds of microscope. Optical microscopes create a magnified image using light from an object. Electron microscopes are much more powerful and use a beam of electrons instead of light.
An electron microscope uses a beam of electrons instead of light. The object to be viewed is placed on a small stand in the middle. An electron gun, similar to the ones in TV sets, fires a beam of electrons down onto the object. As the electron beam scans (passes over) the object, a very detailed picture of the object appears on a TV screen.