Standard Model Theory

In this conference report a summary is given on the theoretical work that has contributed to provide accurate theoretical predictions for testing the standard model in present and future experiments. Precision calculations for the vector boson masses, for the Z resonance, W pair production, and for the g-2 of the muon are reviewed and the theoretical situation for the Higgs sector is summarized. The status of the standard model is discussed in the light of the recent high and low energy data. New Physics beyond the standard model is briefly addressed as well, with special emphasis on the minimal supersymmetric standard model.