Because of the Earth's atmosphere shield, gamma-ray astronomy could not develop until it was possible to get detectors on spacecrafts, and to build large and sensitive ground-based detectors. In this last class, Imaging Air Cherenkov Telescopes (HESS and MAGIC in particular) have recently provided many successful observations. This seminar summarizes the results from the first year of operation of the MAGIC telescope at La Palma, Canary Islands, and presents the developments of the detector and the observational plans for the next years.