MULTILAYER POROUS MEMBRANE

Provided is a multilayered porous membrane that comprises a porous membrane containing polyolefin resin as the main component thereof, and that comprises a porous layer layered on at least one surface of the porous membrane and containing inorganic particles and a binder polymer. The total thickness of the porous layer is 0.5-3.0 µm; the number of pores in the porous layer having an area for the individual pore of at least 0.001 µm is 65-180 per 10 µm of the field of observation; of the pores in the porous layer that have an area of at least 0.001 µm, the proportion therein of pores in the range from 0.001 µm to 0.05 µm is at least 90%; the proportion taken up by the inorganic particles in the porous layer is from 90-99 mass%; and the aspect ratio of the inorganic particles is from 1.0-3.0.