The ANTARES neutrino telescope is located at 2500 meters depth, and is composed by an array of 900 photomultipliers installed for the detection of Cherenkov light emitted by neutrinoinduced muons, after having interacted with matter, and in order to reconstruct their directions. However, besides of being capable to detect high energy neutrinos, neutrino telescopes could mesure the through going of magnetic monopoles in the detector. In this work, were first presented the different methods used in order to calibrate the photomultipliers, which are the heart of a neutrino telescope. The possibility to detect magnetic monopoles with ANTARES was then discussed, and a first analysis optimised for the search for high velocity magnetic monopoles showed the great sensitivity offered by the telescope. Finally, a track reconstruction algorithm was modified, and a new analysis this time sensitive over a wider range of velocities was performed. After the application of the last analysis on the data taken in 2008 with the ANTARES telescope, new upper limits on the upward going magnetic monopole flux, of masses lower than 1014 GeV were obtained, and are the best experimental constraints on their flux for the velocity region β " [0.65, 0.995].
