The invention relates to a container (2) with flexible walls and at least one electrical sensor (3, 3', 3'', 3''', 3'''') which projects into the container interior (6) which is surrounded by the flexible walls, in which container the conductivity or impedance of a medium which surrounds the plates (8, 8', 9, 9', 9''') can be determined between at least two electrically conductive plates (8, 8', 9, 9', 9'''), wherein the plates (8, 8', 9, 9', 9''') are connected to a control and regulating unit (4), which is arranged outside the container interior (6), via connecting lines (10, 11). The invention is distinguished in that at least one first plate (8, 8') is arranged on a closed, free end of a first sheathing (5, 5', 5'''') having a contact area which is exposed to the surrounding medium, and in that the sheathing (5, 5', 5'''', 17, 17''') is in the form of a flexible hose (7) or folding bellows (19, 19'''') through which the electrical connecting line (10, 11) of the plate (8, 8', 9, 9', 9''') is routed to the outside.