Invisibility has always been a fascinating theme for art but starting from Modernity - the novel The Invisible Man by H.G. Wells comes out in 1897 - has taken on new values and characters. Scientific progress and new theories have made it possible to imagine its real and not just magical realization, so that it has become something different from the pure subtraction to the visible. The visible, for its part, has also changed its characters and expanded its field, changes that have in turn been reflected on the conception of the invisible. The result is a significant recurrence of works by artists in the twentieth century in which the invisible has become no longer an oppositional term but a notion and a world of its own characteristics, a state not of denial but of affirmation within the visible itself. Without indulging in the invisible as a metaphor but limiting itself to cases in which invisibility is actually taken on the explicit theme of works and reflection, the text constructs a path in twentieth century art to show the developments of this reflection. Starting from the Surrealism that finds in the invisible a metaphor of the unconscious functioning, then excellent examples have been found above all starting from the art of the 60s, conceptual, povera, that go well beyond the 'dematerialization' and the criticism modernist ‘opticality ', to then move on to the' invisible architecture 'of certain minimalists; then we touch on the theme of camouflage and finally conclude with even more radical examples of the last decades.