<p>A method of liquid mixture separation in which a substance having a molecular weight of 90 or higher is selectively separated from a liquid mixture (31) with a separation membrane. The separation membrane is an MFI-type zeolite membrane (2). The method of liquid mixture separation comprises bringing the liquid mixture (31) into contact with one side of the MFI-type zeolite membrane (2), reducing the pressure on the other side of the MFI-type zeolite membrane (2), and collecting a substance (32) which has passed through the MFI-type zeolite membrane (2). The method of liquid mixture separation enables a given substance to be separated from a liquid mixture without the need of a high energy cost.</p>
