The structure of concrete is difficult to examine because of the difference in size of its components - aggregate measured in centimeters but containing phases 2 to 20 micrometers, smaller than the 20 micrometer thickness of normal thin sections. New methods of examination use sections only 10 micrometers thick. Additionally, impregnation with fluorescent dye enables fine voids, cracks and systems of capillaries to be observed in filtered light. This report describes the methods and equipment used to make such thin sections and details of the microscope needed to observe and photograph them.