A complex of proton accelerators, includes the following functionally interconnected components: a proton source, a cyclotron, at least one target, located either internally or externally to the cyclotron, a medium energy beam transport magnetic channel, a radiofrequency linear accelerator, a high energy beam transport channel towards an area dedicated to the irradiation of tumors with proton beams, as well as a modular system for supplying radio frequency power capable of feeding, independently two or more accelerating modules of the linac. An integrated computerized system controls the complex of accelerators so to carry out, either in alternation or simultaneously, both the production of radioisotopes--for medical, industrial and therapeutical purposes--and the therapeutical irradiation of, even deep seated tumors. The complex of accelerators produces proton beams which, applying the recently developed `spot scanning` technique, are more suited for the tumor irradiation than the ones produced by cyclotrons and synchrotrons.