The invention relates to a long-stroke, contactless nanopositioning mechanism which uses superconducting magnetic levitation to guide a levitating mobile carriage by means of a series of fixed guide elements that ensure a lack of contact between the mobile carriage and the fixed guide elements. The aforementioned mechanism uses control and movement means made up of one or more coils or electromagnets in order to induce movements in the mobile carriage with nanometric resolution in a long stroke by means of electromagnetic interactions. The invention can be used for applications in cryogenic environments such as, for example, interferometric telescopes, components of nanomanufacturing processes and/or confocal microscopes for cryogenic spectroscopy.