Abstract: The purpose of the present invention is to provide a polyamide porous membrane that makes it possible to improve liquid permeability while suppressing deterioration of membrane separation performance. A polyamide porous membrane according to the present invention is formed from a polyamide resin, wherein in structural analysis by X-ray diffraction, the ratio of ? crystals with respect to the total amount of a crystals and ? crystals is not less than 38%.

Abstract: An object of the present invention is to provide a polyamide porous membrane having improved fluid permeation performance. A polyamide porous membrane having a dense layer formed on at least one surface, wherein the polyamide porous membrane has a streak-like recessed portion extending in one direction of a surface of the dense layer, and the streak-like recessed portion has an orientation angle of 0 to 5.0° or 175.0 to 180.0° and an orientation intensity of 1.5 to 2.0 according to predetermined orientation analysis.

Abstract: An object of the present invention is to provide a nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a high amount pf permeate for methanol, and suitable for use as an organic solvent nanofiltration membrane. A nanofiltration membrane formed using a polyamide resin, the nanofiltration membrane having a molecular weight cut-off of 200 to 1,000 and a methanol permeability of 0.03 L/(m2·bar·h) or more.