PROBLEM TO BE SOLVED: To provide a sterilizing device which improves ozone generation efficiency and sterilization efficiency by ozone gas.SOLUTION: The sterilizing device includes: a flow path member 2 which is provided outside a chamber 1 to be sterilized and has a flow path 2a in which air in the chamber 1 to be sterilized enters and returns to the chamber 1 an air blowing device 3 which blows the air in the chamber 1 to the flow path 2a a dehumidification and humidification device 4 which removes moisture from the air that has entered the flow path 2a or adds moisture to the air and an ozone generation device 5 which generates ozone gas in the air from which the moisture is removed.
