Detailed and accurate information about the morphology of supported membranes structures is important for the analysis of their performance and fabrication. In this work it is shown that Focused Ion Beam (FIB) nano-machining can be used to provide such information for polymeric and inorganic membrane layers and composite structures containing those layers. Single-sided cuts are used for scanning electron microscopy (SEM) observations; similar to 100 nm thin slabs obtained with two-sided cuts are used for transmission electron microscopy (TEM) imaging. Details of the FIB milling are provided in addition to examples of cross-sections of polymer, hybrid and inorganic structures. It is shown that the quality of cross-section information, obtained with FIB, is superior to that obtained with transmission electron microscopy of micro-tome sections. In addition it is shown how Energy Dispersive X-ray Spectroscopy (EDS) mapping of FIB cross-sections provides information about the relation between chemical composition and membrane structure that cannot be obtained otherwise. (C) 2014 Elsevier B.V. All rights reserved.