PROBLEM TO BE SOLVED: To provide a technique that exterminates and kills bedbugs with carbon dioxide safely and reliably.SOLUTION: A bedbug extermination method concerning the present invention is characterized in that the bedbugs 9 are buried in an atmosphere of carbon dioxide for 10 hours or more, and reliably killed if the volume concentration of the carbon dioxide is 65% or more in an extermination-completed state. An article 7 to exterminate the bedbugs is stored in the inside of a container 5, and a control small container 8 storing live bedbugs 9 for control is disposed in the container 5. When the carbon dioxide is filled in the container 5, the carbon dioxide enters the control small container 8, and it is confirmed that the bedbugs 9 for control are killed, and thereby the bedbug extermination of the article 7 can be completed. A pressure-regulating valve 11 is installed in the container 7, and the inside of the container 5 is filled with the carbon dioxide. Then, air and/or excessive carbon dioxide initially existing in the container 5 can be evacuated outside the container 5 from the pressure-regulating valve 11 by merely a difference in pressure inside and outside.
