A connecting device (2) for vacuum treatment of wounds comprises a conduit means (4) which can be evacuated, and a carrier means (6), wherein the connecting device can be disposed onto a vacuum dressing (13) which extends over the wound and tightly seals it from the atmosphere. The conduit means (4) communicates with the wound space through at least one opening (16) in a wall (18) of the conduit means (4) facing the vacuum dressing and through at least one opening in the vacuum dressing (13). The conduit means (4) is flexible and flat and the conduit means (4) and the carrier means (6) are formed in one piece in that, starting from a central longitudinal section (10) which forms a longitudinal channel (12), the conduit means (4) merges on both sides into a lateral wing section (8), and the flat conduit means (4) with longitudinal section (10) and lateral wing sections (8) can be widely applied onto the vacuum dressing (13).