Abstract Scanning probe microscopes (SPMs) designed to fit into scanning elec- tron microscopes (SEMs) are now becoming commercially available and you might ask, "Why would I want to put an SPM in my SEM"? The primary reason is that the too forms of microscope are very complimentary. Each microscope extends the power of the other. The SEM can do things that are hard to do with an SPM, and vice versa. Not long after the introduction of the STM and the AFM, a few re- searchers built custom SPMs and installed them in their SEMs. The reports of these projects to build hybrid microscopes and examples of the data they produced can be found in the scientific literature.