This chapter reviews the fundamentals of electron tomography and highlights aspects that are unique to using electrons. Each imaging mode used for electron tomography is discussed. Their benefits and drawbacks are outlined with examples of the diverse range of materials now being studied. Topics covered include tomography using the electron microscope, alignment and reconstruction, bright-field and dark-field electron tomography, HAADF STEM tomography, and EFTEM tomography. Keywords:bright-field electron tomography,
dark-field electron tomography,
HAADF STEM tomography,
EFTEM tomography