Abstract: Intelligent sequential illuminating device for photodynamic therapy of surface tumors that comprises: the module for illumination and detection, module for signal processing and control and module for power supply, of which the module for illumination and detection consists of the violet light emitting diodes (405) and the red light emitting diodes (640), where the violet light emitting diodes serve for fluorescence excitation of the photo reactive agent and the red light emitting diodes have twofold purpose: for emission and therapeutic red light and for detection of the red fluorescent light caused by illumination of the violet light emitting diodes. The module for signal processing and control manages a work of the light emitting diodes so that the violet light emitting diodes are activated into the determined sequences during which the red light emitting diodes measure the level of ppix fluorescence.