PURPOSE: To carry out the drying of a wet porous hollow fiber of regenerated cellulose, without deteriorating the fiber, by substituting the water in the hollow fiber with a specific organic solvent, and drying the fiber under tension while applying pressure of gas to the hollow part.

CONSTITUTION: The water in a cellulosic hollow fiber is substituted with an organic solvent having a boiling point of ≤70°C, solubility of ≥10wt% in water, and free from hydroxyl group, and the fiber is dried under a tension higher than 0.1g/d and lower than the tensile breakage strength of the fiber, while applying pressure to the hollow part with a gas having a relative humidity of ≤70%. The pressure is ≥100mmHg and lower than the burst strength of the fiber.

USE: Artificial kidney, artificial liver, artificial pancreas, ultrafiltration membrane, etc. of filtration/dialysis-type or of filtration-type.