PROBLEM TO BE SOLVED: To provide a decontamination system which does not require large-scape installations, e.g. a large-diameter duct or a heater for prevention of condensation, allows long-distance piping for each of a plurality of to-be-decontaminated chambers and supplies accurate amounts of a gas for decontamination to each of the chambers.SOLUTION: A decontamination system includes compression air generation means and decontamination liquid supply means and is provided with a mixing gas/liquid regulator and a gas generator for each of to-be-decontaminated chambers. The carrying distance of the mixing gas/liquid supply piping which communicates the mixing gas/liquid regulator with the gas generator is greater than the carrying distance of the decontamination liquid supply piping which communicates the decontamination supply means with the mixing gas/liquid regulator.
