Abstract: A permeable membrane excellent in biocompatibility, produced by forming coagulation by melting method in the form of a membrane a terminal-modified polyamide, i.e. a polyether amide comprising component units represented by the following structural formula (I), (II), (III), or (IV), possessing hydrocarbon groups of one to 22 carbon atoms at the terminals thereof, and having a molecular weight in the range of from 10,000 to 100,000, said terminal-modified polyamide being such that the number of said hydrocarbon groups is in the range of from 5 to 100% based on the number of all of the terminal groups of said polyether amide, placing said membrane in contact with a medium capable of swelling or partially dissolving said membrane, and further placing the resultant altered membrane in contact with a solution consisting mainly of a nonsolvent for said polyether amide. ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 are independently a linear or branched alkylene group of two to four carbon atoms, R.sup.4,R.sup.

Abstract: A permeable membrane excellent in biocompatibility, produced by forming coagulation by melting method in the form of a membrane a terminal-modified polyamide, i.e. a polyether amide comprising component units represented by the following structural formula (I), (II), (III), or (IV), possessing hydrocarbon groups of one to 22 carbon atoms at the terminals thereof, and having a molecular weight in the range of from 10,000 to 100,000, said terminal-modified polyamide being such that the number of said hydrocarbon groups is in the range of from 5 to 100% based on the number of all of the terminal groups of said polyester amide, placing said membrane in contact with a medium capable of swelling or partially dissolving said membrane, and further placing the resultant altered membrane in contact with a solution consisting mainly of a nonsolvent for said polyether amide. ##STR1## wherein R.sup.1, R.sup.2, and R.sup.3 are independently a linear or branched alkylene group of two to four carbon atoms, R.sup.4, R.sup.