The aim of this paper is to present the core of Kant´s critique of traditional metaphysics and ontology as a transcendental semantics that allows reformulating the problem about the objects and their reality. In order to achieve this purpose, we propound a paper divided in two parts: 1. A brief justification of Kant’s semantics interpretation; 2. A work program based on a semantics comprehended as a fundamental part of a method of resolution of philosophical problems. Basically, we can state that the critical position against traditional metaphysics and ontology leads to the question upon: how are a priori synthetic judgments possible? This question leads to its conditions of possibility, that is: sensible representations; intellectual representations; syntactic rules; semantic rules (or referential rules, on the relation between intellectual representations and some sort of sensibility or affection); the operator of the syntactic and semantic rules (subject, man, human nature, gender, people etc.). This is what we call the core of Kant’s critique and with which we may begin to solve philosophical problems even beyond those presented by our philosopher. As such, we are briefly going to observe the following steps: 1. From metaphysics in its various senses to the ontology of sensible objects; 2. A critique of pure reason against dogmatic metaphysics; 3. Criticism as semantics; 4. The semantic project and the kinds of judgments; 5. Human nature and the theory of judgment; 6. The work program within Kant’s own work; 7. Subsequent results of Kant’s project