Sixty-five grams of sudachi (Citrus sudachi Hort. ex Shirai) essential oil from 18 kg of peel was isolated by a modified solvent extraction (MSE) in a semi-preparative scale with a hand-screw pressing instrument and a solution of pentane and dichloromethane. Twenty-four compounds were newly identified. The essential oil retained its original aroma without any off-flavor. The odor character of sudachi essential oil prepared by MSE method was described by means of odor impact spectra (OIS). The combination of preparing a large quantity of the oil and the OIS method enabled clarification of the potent aroma components. Thus, (E,E)-α-farnesene, (E)-β-farnesene, diisopropyl disulfide, cumin aldehyde and dill ether were newly selected as the aroma-active compounds.