The alkali activation of fly ashes produces a solid and compact material having similar properties to those of portland cement (PC) with characteristics of sustainable high value; these materials with high silica and aluminum are referred to as geopolymers. These new materials are a new generation of environmentally friendly cement, so it is very important to study their properties to validate their implementation; for which the application of new techniques currently being used. The work presented in this study focuses on establish the usual procedures of the techniques of X-ray diffraction (XRD), Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) in its specific application to geopolymer base, or also called fly ash. Likewise, is determined the behavior of these materials for each of the above techniques.