We ll approach the notion of object in Wittgenstein s Tractatus Logico-Philosophicus (1921), initially from the so-called substance argument. The discourse about necessary conditions for the propositional sense cannot be treated in terms of truth or falsity in the Tractatus without resulting in a infinite regress. Such a situation is avoided by postulating a substance made up of simple objects, thus ensuring the assumed total determination of sense. Passages from the Notebooks (1914-1916) suggest that the idea of simples is given in the ideia of logical analysis and is reached without the necessity of examples for objects. Another early Wittgenstein s remarks provide examples for objects based on itens of phenomenical nature, such as a point in the visual field. An important analogy for the phenomenical approach for the object, which is found in the aphorisms 2.013-2.0131 of Tractatus, presents a problem for the absolute simplicity. This problem concerns the notion of form, a concept that attributes an ontological dependence to the object given by its essencial capacity of occurrence in atomic facts. The form of the objects results from an appropriation of the Context Principle used by Frege in his Grundlagen der Arithmetik (1884) and differs from the notions of pictorial form and logical form. The dependence assigned to the object through its form contradicts the independent subsistence established by its simplicity. The Tractarian object results from necessary demands for determination of propositional sense, reached by means of an clarificatory analysis which prioritizes the transformative and regressive modes of analysis. Simplicity and Context Principle are, under this perspective, rules of a syntax for a logical or significative use of language, which are reflected in the Tractarian ontology through the ideia that the logico-philosophical investigation of language reveals essencial aspects of the intimate structure of the world.