PURPOSE: To obtain the title microporous membrane capable of preventing the elution of a contaminant into the filtrate and having permanent hydrophilicity by chemically bonding an amine compd. to the microporous membrane made of polyvinylidene fluoride.

CONSTITUTION: Polyvinylidene fluoride is dissolved in dimethylformamide, the soln. is cast on a glass sheet, and the sheet is dipped in an aq. soln. of dimethylformamide, etc., to solidify the soln. The solidified membrane is washed with water, and dried to obtain a microporous membrane with the dimethylformamide as a micropore forming material. The membrane is dipped in a soln. of ethylenediamine as the amine compd. in isopropyl alcohol, etc., to allow the polyvinylidene fluoride to react with the amine compd. The reaction product is washed with water, and dried to obtain a hydrophilic microporous membrane.