Patent ID: 8851297

Claim:
A process for producing a composite semipermeable membrane comprising: forming a skin layer including a polyamide resin obtained by reaction between a polyfunctional amine component and a polyfunctional acid halide component on the surface of a porous support; and performing a treatment with additives onto the porous support by contact of an aqueous solution including at least one kind of additives selected from the group consisting of an antioxidant, an antibacterial agent, an antifungal agent, and a moisturizer, only to a face without the skin layer of the porous support, wherein the treatment with additives onto the porous support is performed by immersion of the composite semipermeable membrane in the aqueous solution in a state where the skin layer is closely contacted to a roll to thereby yield a composite semipermeable membrane wherein the porous support contains 95% by weight or more with respect to the whole composite semipermeable membrane of the one or more additives.