MAGIC: An Instrument for Ground-Based Gamma-Ray-Astronomy Martin Merck Institut fuer Theoretische Physik und Astrophysik Wuerzburg, Germany MAGIC is an innovative imaging air cherenkov telescope designed to achieve the lowest possible energy threshold. The novel techniques used to build this telescope will be discussed. Based on the expected performance of the telescope we will review the physics goals and potential of the telescope. A main scientific goal will be the the precise measurement of the high energy spectra of AGNs at different redshifts and the determination of the cosmological gamma-ray horizon. Prospects on detecting VHE gamma-rays from GRBs will be presented. Finaly the accessible parameter space for searching for cold dark matter using the neutralino annihilation line will be reviewed.