A device for a procedure for preoperatively preparing patients with progressive drug-resistant fiber-cavernous tuberculosis also for treatment of other diseases, as lungs and other organs is developed. The device performed process of treating infected cavities and contains: mercury tube, focusing system for selection of segment of the radiation spectral band 250-500 nm, optical guide with connectors and a puncture needle. Use the tube with high pressure mercury vapor as a radiation source allows to obtain the broadband photon radiation for treatment more efficient and for recovery time reduce. It also provides a substantial simplification of the device and reducing its costs. The device was used to approve the method of treatment of infected cavities by means of endocavitary broadband irradiation. In the experiments we used cultures of Escherichia coli and Candida albicans. Effect of annihilation of bacteria colony is almost directly proportional to the duration of exposure and complete suppression occurs within 2 min.