Astronomical and cosmological observations of the past 80 years build solid evidence that atomic matter makes up only a small fraction of the matter in the universe. The dominant fraction does not interact with elec-tromagnetic radiation, does not absorb or emit light and hence is called Dark Matter. So far dark matter has revealed its existence only through gravita-tional effects. The strongest experimental effort to find other evidence and learn more about the nature of the dark matter particles concentrates around Weakly Interacting Massive Particles which are among the best motivated dark matter candidates. The two main groups of experiments in this field aim for indirect detection through annihilation products and direct detection via ...