Nanometer-sized films of clinker phases have been prepared using electron-beam evaporation methods with the aim to produce suitable samples for nanoscale studies of hydration mechanisms and nanomechanical properties of cementitious materials. After deposition on a silicon substrate, film thicknesses and mineralogical composition were characterized by optical interferometry (OI) and grazing-angle X-ray diffraction (GAXRD), respectively. Chemical composition of samples was determined by X-ray photoelectron spectroscopy (XPS) of samples of a few tens of nanometers in thickness. Results from the GAXRD and XPS analysis show that samples quickly react with the atmosphere and show clear signatures of partial hydration and carbonation. However, quantitative analysis shows that the Ca:Si ratio of the deposited film is the same as in the bulk starting material.