An apparatus for the treatment of plastics material containers includes at least one movable support which is arranged in an isolator room to which a sterilization agent is capable of being supplied. The isolator room is constructed in at least two parts, and a first boundary of the isolator room is fixed in position during a movement of the movable support, while a second boundary of the isolator room is connected to the apparatus in such a way that it is suitable, during a movement of the movable support, for following this movement. The apparatus has at least one device for supplying the sterilization agent into the isolator room. The supplying device is suitable for acting with the sterilization agent upon the parts of the apparatus movable relative to this device and situated inside the isolator room.