Optical microscopy allows observation of details of the order of micrometers. In an electron microscope that uses an electron beam to make an image, the resolution is a thousand times better. It becomes possible to observe details of the nanometer (nm) in conventional mode and order of the Angstrom (1 Å = 0.1 nm) in high resolution mode. This technique requires a delicate preparation of samples to be sufficiently thin (≤ 100 nm) to allow the passage of electrons to an observation in transmission. The transfer of energy between incident electrons and atoms in the sample are operated through energy loss spectroscopy (EELS) and X-ray emission (EDX) to perform a chemical analysis of the observed object. The purpose of this paper is to show, through some examples, the potential of transmission electron microscopy and related techniques in the study of structure and composition of heritage materials.