Abstract: A pass-through system (110) which is arranged between at least one freely accessible area (100) and at least one area which is only accessible to authorized people comprises: a pass-through (5) area which is marked on the floor and/or defined by mobile blocking devices (13); at least one image capturing device (7); at least one image processing device (8) and at least one alarm triggering device (9). At least one specific signal can be transmitted to the alarm triggering device (9) by the image processing device (8) when at least one person respects or violates the rules which govern access, passage or exit from the pass-through system (110) or if objects have been left behind in the pass-through system (110).