There is a substantial worldwide waste treatment problem in the citrus industry."Yuzu" (Citrus junos Sieb.ex Tanaka),a sour and fragrant citrus fruit,has been cultivated for more than a thousand years,mainly in Japan and Korea,and the annual production of those countries amounts to approximately 20,000 and 15,000 tons,respectively.Yuzu has a fresh,pronounced and strongly characteristic aroma in comparison with any other citrus fruits,and the volatile components of yuzu have been studied by many researchers.Recently,global demand for yuzu essential oil has increased due to developments in the fields of fragrance and aromatherapy.We developed a steam-distillation extractor equipped with a reduced pressure supersonic generator to recover high quality essential oil from yuzu peel waste.