The research developed for recognition and definitions of a microstructure of a given material still has many challenges to be overcome. The aim of this book is to present ImageJ free software tools, implementation of routines and techniques, in order to ensure the quantitative analysis of microstructures of materials, presenting significant and important contributions to the advancement in characterization of materials in industries in general. In the microstructures study, zirconia-based ceramics were sintered at temperatures of 1450, 1500, 1530 and 1600 °C with times of 2 and 4h, obtained by scanning electron microscopy (SEM).