The future accelerators need ion beams with higher charge state and higher current. This demand will be met by the “third generation Electron Cyclotron Resonance Ion Sources” (ECRIS) which will make use of improved plasma confinement by means of higher magnetic field and of higher microwave frequency, thus boosting the performance of nowadays ECRIS operating at the frequency of 14 and 18 GHz. The possibility to obtain confining fields exceeding 4 tesla, by means of special design of NbTi superconducting magnets, open the way to a new operational domain, at the typical frequencies of gyrotrons, above 28 GHz, with plasma densities never achieved before in ECRIS (1013 cm^–3 and higher). The test of SERSE at 28 GHz, confirming the theoretical frame on which the third generation ECR sources design is based, will be presented; a synthetic review of the new generation ECRIS is carried out, with a particular emphasis on the design of the GyroSERSE source. Finally, the scheme of an innovative hybrid source will be outlined and a short description of the ECLISSE (Electron Cyclotron Resonance ion source Coupled to a Laser Ion Source for charge State Enhancement) experiment is hereinafter presented.