TORE SUPRA has now been upgraded to handle high power plasmas for very long duration. It came back into operation in 2001, and the goals are to extend the performances, in power and in duration, to be expressed in terms of energy. The design is such that a plasma discharge of 25 MW during 1000 s could be sustained, with actively cooled components in a steady-state condition. This corresponds to 25 GJ, orders of magnitude above other existing tokamaks and relevant to ITER conditions. The importance of diagnostics for missions other than physics understanding increases, such as machine operation or safety control. All TORE SUPRA diagnostics have been revisited to take into account these new constraints. Only a few of them did not need to be modified, most had to be adapted, upgraded, or even completely rebuilt. The main constraint deals with the thermal load on diagnostic components, the need to optimize the geometry and develop specific protections often with active cooling. The specific developments now implemented and operational on TORE SUPRA will be presented. Another requirement concerns the need for more control loops in order to maintain optimized modes of plasma operation for very long periods. Diagnostics are operated in real time, with the ability to transmit any kind of pertinent information on a fast time scale. This requires strict procedures, higher reliability, and stability of calibration of the relevant diagnostics. In addition, data can be accessed in real time, without waiting for the end of the pulse.