The stoichiometry, microstructure and surface composition of MnSb have been investigated using X-ray photoelectron spectroscopy, electron diffraction and microscopy. Epitaxially grown samples were exposed to ambient air for several weeks and methods for preparing clean, stoichiometric and smooth surfaces were investigated. Air-stored sample surfaces are chemically stratified but dominated by Mn oxides 4-5 nm thick. These oxides are difficult to remove by ion bombardment and annealing (IBA), but a brief etch in HCl removes them very efficiently. It leaves the surface Sb-rich, and clean, smooth and stoichiometric surfaces are then readily recovered by IBA. These surfaces exhibit a (2 x 2) surface reconstruction with atomically. at terraces. This reconstruction can be reversibly changed to a (1 x 1) by Sb deposition and annealing. (C) 2008 Elsevier B.V. All rights reserved.