Recent advances in automating tissue processing, data collection and analysis have spurred new interest in electron microscopy (EM) as a tool for neuroscience. It is now possible to acquire three-dimensional EM-resolution data sets which are large enough to reconstruct circuits between neurons at the synaptic level. This talk will discuss the ATUM (Automatic Tape-collecting Ultra-Microtome) method for serial sectioning followed by Scanning Electron Microscopy (SEM) imaging, as well as processing and analysis of multi-Terabyte nanometer-resolution 3D image data sets.