In recent years, polyethylene and polysulfone membranes have been used for plasma separation in Japan. The polyethylene membrane, manufactured by melt spinning method, has a sponge-like symmetric structure. The plasma separator Plasmaflo OP (Asahi Medical, Tokyo, Japan) with a polyethylene membrane shows excellent performance and safety for plasma separation. More than 20 indications for therapeutic plasmapheresis are reimbursed in Japan. Future development is expected in new membrane designs for new indications or advanced plasmapheresis methodologies.