PURPOSE: To separate an org. solvent at relatively high temp. by a hollow fiber membrane module.

CONSTITUTION: A least one end part of the bundle of hollow fiber membranes is immersed in a resin compsn. melt consisting of 5-99wt.% of low density polyethylene wax and 95-1wt.% of a low density olefin polymer with a melt index of 50 or more to be sealed and fixed to a casing. Polyethylene is contained in the wax and the polymer. The density of the wax is 0.94g/cm2 or less and the mol.wt. thereof by a viscosity method is 20000 or less. When the wax and the polymer are together used, a hollow fiber membrane module relatively high in the adhesion to hollow fiber membranes and heat resistance and having a sealed and fixed part excellent in solvent resistance is obtained.