Abstract: A tubular membrane module for separation providing a plurality of perforated support tubes having a semipermeable membrane for separation provided on inner surfaces thereof, a cylindrical case having a permeated solution port provided on a drum portion thereof, a pair of first and second plastic headers attached to both ends perforated support tubes for making the perforated support tubes be communicated and header connecting means, the first header being divided into a first header outer portion having a feed solution inlet port and a concentrated solution outlet port provided on an outer surface thereof and a plurality of first communication ports which are groove-shaped provided on an inner surface thereof, and a first header inner portion held between the first header outer portion and the case and having first openings for fitting the perforated support tubes which correspond to the first communication ports, and the second header being divided into a second header outer portion having a plurality of sec