The device was one of the most revolutionary concepts formulated by Michel Foucault for the study of ideologies and systems of thought. Despite this, it was not defined by the French philosopher. Recently, a refreshing of the idea has been developed by the Italian Giorgio Agamben, for whom the notion of device is associated with the political space and the legal system of the governed, where models of control and pollution models remind us that we were once something different from what we are today. This article presents the notion of a device as everything that facilitates the recognition of the human, using, for this, subjectivity. It is the image of the subject in the car, in the bar, in the school, in the economy, in politics, etc., those that delineate and legitimize the constitutive features of a subject that feeds from itself. The subject is reflected in the device, and it guides and defines it.