The gas-phase fluorination of plastic articles is effected in a reaction chamber 1 into which the plastic articles to be fluorinated are introduced. The gas-phase fluorination is effected at normal or atmospheric ambient pressure of about 1 kPa in the reaction chamber. The gas-phase fluorination can be carried out statically or dynamically. The flushing carried out before the gas-phase fluorination for complete or partial removal of atmospheric oxygen from the reaction chamber 1 can also be effected at atmospheric pressure in the reaction chamber. The reaction chamber 1 is equipped with a cover 2 and metering valves V0, V1, V2 for air, inert gas and gas mixture comprising fluorine and one or more inert gases are present on the entrance side of the reaction chamber, which is not vacuum-tight and hence also cannot be evacuated. The metering valves are connected to the reaction chamber 1 via a flow meter 4. A release valve V3 and a flow-through/shut-off valve V4 are arranged in an exhaust gas line 8 of the reaction chamber 1.