An object of the present invention is to provide a porous hollow fiber membrane for the treatment of a protein-containing liquid where the substances to be removed such as small-sized virus contained in a solution can be efficiently separated and removed and, at the same time, useful substances to be recovered such as protein can be efficiently permeated and the decrease in the permeation characteristics thereof with elapse of time is small. The porous hollow fiber membrane for the treatment of a protein-containing liquid of the present invention is characterized in that the membrane comprises a hydrophobic polymer and a hydrophilic polymer, its permeability for pure water is 10 to 300 L/(h·m2·bar) and, when a 0.5% immunoglobulin solution is subjected to filtration at a constant pressure of 1.0 bar for 60 minutes in dead-end filtration mode, its filtration time and accumulated amount of recovered filtrate are substantially in a linear relation.
