The Max-Planck-Institut für Plasmaphysik (IPP) is concerned with investigating the physical fundamentals underlying a fusion power plant which – like the sun – is designed to gain energy from the fusion of light atomic nuclei. The two concepts for the magnetic confinement of fusion plasmaTokamak arrangement and stellarator principle – are examined for their power plant suitability at the IPP. In Garching, the ASDEX-Upgrade Tokamak and the WENDELSTEIN 7-AS stellarator are operated. The successor WENDELSTEIN 7-X is under preparation at the branch institute of IPP in Greifswald. The work of the IPP is integrated in national and European programmes as well as in world-wide co-operation. On the European level, the IPP presently involved in the largest fusion experiment in the world JET (Joint European Torus). At the same time, IPP co-operates in the world-wide project for the International Thermonuclear Experimental Reactor ITER.