A device for measuring a pressure in a pressurized vessel with an at least partially flexible wall. The device includes a sensor head and a device for pressing a contact surface of the sensor head against the wall. The sensor head has a detection region of the contact surface and a support edge that surrounds the detection region and is arranged in a continuation of the contact surface. A detection device is provided in the detection region for detecting a measured value for a force or pressure. An evaluation unit evaluates a progression of the measured value during a movement of the sensor head relative to the wall. A contact measured value p* is determined from a portion of the progression indicating that the pressure acting on the detection region is at least substantially equal to the pressure acting on the support edge. A pressure value is assigned to the contact measured value p*.