One of the most difficult issues of the modern medicine is the combat against the infectiuos diseases. At the same time the problem of the increasing resistence of the infected microorganisms against the most uptodate antibacterian preparations (the chemotherapy problem), is becoming more urgent. Because of this we propose to develop a device for photosanitation with ultraviolet C radiation of the human cavites populated with colonies of unspecific or/and tuberculosis microflora. A tube of mercury at high presure serves as radiation source. The ultraviolet radiation is guided into the cavites through the optic fiber, being inserted into the cavity through a microsonde.