The altarpiece dedicated to San Antonio de Padua was made of wood assembled and self-supporting structure attached to the wall. It is a straight plant altarpiece designed to withstand sculptures. This master piece belongs to the a set of Baroque altarpieces preserved in the state of Campeche and is located in San Roque Church in the City of San Francisco de Campeche, Mexico. This altarpiece was decorated following the traditional technique of the seventeenth century in Mexico, a technique derived from Spain. According to literature sources we know that the strata are the wood, the imprimatura, the pictorial strata and metal sheets that make the golden color and corladuras. The characterization of the constituent materials was of great importance for the interpretation of the constructions system and manufacture of the decoration. The present study shows the results of analysis techniques such as optical microscopy, Particle Induce X Ray Emission (PIXE), and X Ray Florescence Spectroscopy (XRF) and interpretation of the different layers constituting the altarpiece of San Antonio.