A portable device (2) to generate a vacuum for the medical treatment of wounds on the bodies of humans or animals has a vacuum-producing suction pump (90) in a first housing part (4) of the device and a vessel (10) for receiving body liquids. Vacuum is applied for vacuum communication between the suction pump (90), the vessel (10) and a suction tube (82) leading to the body. A pressure sensor (94) measures the pressure in a tube section (88) and a programmable electronic control unit (100) controls the suction pump (90) in dependence on pressure values measured by the pressure sensor (94). The electronic control unit (100) deactivates the suction pump (90) if a rate of change in pressure (Deltap/Deltat) detected by the pressure sensor (94) exceeds a defined threshold value toward decreasing vacuum.
