To provide a decontamination system for easily decontaminating a human body contaminated with a contaminant.

This decontamination system 1 is configured to decontaminate the human body contaminated with the contaminant (e.g. an NBC (nuclear, biological, chemical) substance) by spraying and pouring ozone water from an ozone water spraying device 60. The ozone water spraying device 60 can spray the ozone water such that a difference between a pressure just before the ozone water is sprayed from spray ports and a pressure after the ozone water is sprayed from the spray ports becomes small.