In this text, we have sought to demonstrate how we can interpret theobject as an appearance and as a reality, according to the philosophy of Peirce, asexplained based in triadic logic of symbol interpretation. The construction of thislogic is developed in phenomenology, through the categories of Firstness,Secondness and Thirdness, the last one playing the main role in the works of theauthor. It acts as a mediator for an action of trivalent nature, refuting all diadicconcepts, or diadic representations of sign-object, or object-sign, thus "breaking"with the pretention of interpreting in a single absolute way the traditionaldichotomy.The first part of this dissertation deals with the development of structurein the philosophical thinking of Peirce, evincing the importance of pragmatism as amethod of scientific research. The second part discusses the problem ofinterpretation, in wich the object as an appearance is studied in phenomenology, andthe object as a reality within the Metaphisics of the author. The object isdecomposed by the analysis of these sciences and later reconstituted in Semiotics,remade in its totality, in the sign-object-interpreter triad. Therefore, to ensureinterpretation as a triadic process, based on this triad, it is necessary for Semiotics toplay the main role in the elaboration of this process