The invention relates to a therapeutic device to promote the healing of a wound, comprising a porous paid which is permeable for fluids to place on the wound, a bandage to cover the wound and to provide an essentially airtight seal around the wound, a drainage line connecting the pad with a suction pump so that suction can be applied to the wound to draw the fluids away from it, whereby the line is connected to the suction pump via a canister to collect fluid sucked from the wound, a connector to connect the pad to the drainage line, means to determine a prevailing wound pressure basically comprising the wound and this surrounding skin area, as well as a control unit to control the wound pressure. In order to generally improve metrology with the goal of making possible a more reliable and more secure dressing of the wound, and also to design metrology in an especially simple and error-free way, it is proposed that the pad interconnect the suction pump solely via the drainage line.