LAMINATED POROUS FILM FOR SEPARATOR

Disclosed is a laminated porous film for a separator of a battery that, while having excellent air permeation performance which contributes to electric performance, has a shutdown property which is one of properties important from the viewpoint of ensuring safety. The laminated porous film is characterized in that the laminated porous film comprises layer A formed of a porous layer composed mainly of a polypropylene resin and layer B formed of a porous layer composed mainly of a polyethylene resin, has a ²-activity, and has an electric resistance of not more than 10© at 25 °C and an electric resistance of not less than 100© after heating at 135 °C for 5 seconds and/or an air permeability of not more than 1000 sec/100ml at 25 °C and an air permeability of not less than 10000 sec/100ml after heating at 135 °C for 5 seconds.