It is described an irradiation device (10； 100) of a paste-type composition (C) comprising a container body (12； 120) equipped with a longitudinal through opening (14； 140), for the transit of the paste-type composition (C) to be irradiated, and with a dispensing head (18； 180) extending from the longitudinal through opening (14； 140)； at least one irradiation element (24； 240) arranged in the container body (12； 120) and suitable for irradiating the paste-type composition (C) in transit in the longitudinal through opening (14； 140)； and an energy source (26； 260) also arranged in the container body (12； 120) and in electrical connection with the at least one irradiation element (24； 240). It is also described a cartridge (50) for application on a treatment site of a paste-type composition (C) to be irradiated, the cartridge comprising a tube (30； 300) of paste-type composition (C) able be removably associated with such a irradiation device (10； 100).
