[en] An ECRH (Electron Cyclotron Resonance Heating) system capable of delivering 2.4 MW CW is presently under development at CEA (Commissariat a l'Energie Atomique) Cadarache, for the Tore Supra experiment, to provide plasma heating and current drive by Electron Cyclotron Resonance interaction. The generator is planned to consist of six gyrotrons TH 1506 B developed thanks to a collaboration between TED (Thales Electron Devices) and European laboratories; the gyrotrons are specified to provide RF waves with a frequency of 118 GHz and a unit power of 400 kW (500 kW) for a pulse length up to 600 s (5 s). At present, one prototype and one series tube are installed, which were first tested on dummy loads and then on plasma, individually and together. Even though the specification was not fulfilled, a record pulse of 300 kW during 110 s was achieved by the series gyrotron; the pulse was stopped by a strong degassing within the tube, due to the overheating of the internal mirror box. This seems to be the consequence of spurious frequencies generated in the injector. New upgraded tubes will be developed by TED and the next gyrotron is planned to be delivered during summer 2003. At the end of 2001, 800 kW generated by the two existing gyrotrons were coupled to the plasma, using various polarizations and injection angles allowed by the mobile mirrors of the antenna; the power was modulated at frequencies between 2 Hz and 25 Hz, on both tubes. As a result, about 50 ECRH pulses have successfully been coupled to the plasma, leading to a first comparison of theoretical deposition profiles with the experimental profiles observed through the ECE diagnostic. (authors)