A method and a device for condensing a water-soluble organic matter, which can collect a highly concentrated water-soluble organic matter, save energy, and reduce cost of the device by reducing a membrane area.According to the present invention, the permeability ratio of a vapor-permeation separation membrane disposed at least immediately before a final outlet on a non-permeation side in the separation membrane device is lower than those of the other vapor-permeation separation membranes while a hybrid process combining distillation by the distillation column with membrane separation by the separation membrane devices including a plurality of vapor-permeation separation membranes is used and energy saving performance is maintained. Therefore, a highly concentrated and condensed component of a water-soluble organic matter is obtained. In addition, it is possible to reduce a membrane area of the vapor-permeation separation membranes in the whole separation membrane devices and to provide a technology leading to cost reduction.