A device for preparing plastic containers (16) for being put into use. The containers (16) are molded to one another in container blocks (17) side by side along separating lines (18). Along the separating lines, the individual containers (16) can be separated from one another for use. Cutter blades (28) are movably guided at least in part along the separating line. The cutter blades (28) are, arranged on a carriage (64) movably guided back and forth between a position of use and a position of non-use. In the position of use, the r cutter blades (28) are raised by a swivel device (54, 78, 82) and move along the separating lines (18). In the position of non-use of the cutter blades, the cutter blades are lowered at a distance from the containers (16) to be separated from one another.