The upgraded EU 1 MW, 170 GHz continuous wave (CW) industrial prototype gyrotron (TH1509U) for Electron Cyclotron Resonance Heating and Current Drive (ECRH&CD) in ITER was tested at the Karlsruhe Institute of Technology (KIT). The gyrotron surpassed the performance of the previous TH1509 tube. In particular, TH1509U delivered (i) 0.9 MW in 180 s pulses (max. pulse length of the KIT test stand) and (ii) more than 1 MW at a pulse length limited to 40 s, due to a problem with the test stand cooling circuit at that time. In addition, it was possible to demonstrate gyrotron operation at (iii) 0.5 MW in 1600 s pulses.