Odorizer device for gas distribution networks, comprising: - a tubular jacket developing according to a longitudinal axis (X); - a feeding element suited to absorb an odorizing substance and to transfer it through evaporation, arranged in said tubular jacket ; - coupling means for the stable connection of said tubular jacket to a duct ; characterized in that it comprises: - a containment element slidingly arranged in said tubular jacket according to said longitudinal axis (X); - adjusting means suited to maintain the mutual axial position between said tubular jacket and said containment element and suited to be operated to cause said containment element to slide with respect to said tubular jacket between a first position, in which an end portion of said containment element is arranged outside of said tubular jacket , and a second position, in which said end portion is arranged inside said tubular jacket ; - gas tight means interposed between said tubular jacket and said containment element ; - a cavity belonging to said containment element , developed according to the direction of said longitudinal axis (X) between an inlet mouth opposing said end portion and one or more outlet mouths defined on the external surface of said end portion , the whole of said outlet mouths extending over a portion of said longitudinal axis (X) whose length exceeds the maximum width of said outlet mouths according to a direction that is orthogonal to said longitudinal axis (X), said outlet mouths being configured in such a way that they are closed by said tubular jacket when said containment element is arranged in said second position; said feeding element being arranged in said cavity . - a tubular jacket developing according to a longitudinal axis (X); - a feeding element suited to absorb an odorizing substance and to transfer it through evaporation, arranged in said tubular jacket ; - coupling means for the stable connection of said tubular jacket to a duct ; - a containment element slidingly arranged in said tubular jacket according to said longitudinal axis (X); - adjusting means suited to maintain the mutual axial position between said tubular jacket and said containment element and suited to be operated to cause said containment element to slide with respect to said tubular jacket between a first position, in which an end portion of said containment element is arranged outside of said tubular jacket , and a second position, in which said end portion is arranged inside said tubular jacket ; - gas tight means interposed between said tubular jacket and said containment element ; - a cavity belonging to said containment element , developed according to the direction of said longitudinal axis (X) between an inlet mouth opposing said end portion and one or more outlet mouths defined on the external surface of said end portion , the whole of said outlet mouths extending over a portion of said longitudinal axis (X) whose length exceeds the maximum width of said outlet mouths according to a direction that is orthogonal to said longitudinal axis (X), said outlet mouths being configured in such a way that they are closed by said tubular jacket when said containment element is arranged in said second position; <EOS>