An overview of the high-energy emission from the galactic center

The Galactic Center is a prominent source in X-rays and gamma-rays and the study of its high-energy emission is crucial in understanding the physical phenomena taking place in its dense and extreme environment, phenomena that are possibly common to other galactic nuclei. However this emission is also very complex and consists of both thermal and non thermal radiation produced by compact and extended sources, surrounded by more diffuse components. In spite of the fundamental advances obtained in the last ten years with Chandra, XMM-Newton, INTEGRAL, HESS and Suzaku several questions remain open to investigations. I will review here the main results and the open issues on the high-energy diagnostic of the galactic nuclear activity. (authors)