| abstract |
To provide a composite semipermeable membrane having both high peel resistance and water permeability. A composite semipermeable membrane comprising a substrate and a microporous support membrane comprising a porous support layer provided on the substrate, and a separation functional layer provided on the porous support layer, The porous support layer has a multilayer structure having a first layer, a second layer, and a third layer, and a peel strength between the substrate and the porous support layer is 1.0 N / 25 mm or more. . [Selection figure] None |