To provide a method for using peppermint oil with improved repelling effect as a harmful organism repellent, and to provide a device therefor.

Peppermint oil 10 as a harmful organism repellent is reserved in a vessel 30 to impregnate a wick stood in the vessel with the peppermint oil 10 which is then heated and transpirated. The other objective device is made up of the vessel 30 to reserve the peppermint oil 10 as the repellent, the wick 3 stood in the vessel 30 to impregnate it with the peppermint oil 10, a heater 4 to heat and transpirate the peppermint oil 10 impregnated, and a temperature control means for heating the peppermint oil 10 impregnated.