Disclosed is a method for producing a laminated porous polyolefin film,
the method comprising steps of: providing a pair of tools for
thermocompression bonding two resin films therebetween, laminating two
films each comprising at least one layer made of a polyolefin resin
composition comprising 100 parts by weight of a polyolefin resin having a
melt index of 0.1 g/10 min or less and 80 to 300 parts by weight of a
filler to form a laminated film by piling and thermocompression bonding
the films between the thermocompressing portions of the tools, wherein
the surface temperature of each thermocompressing portion is adjusted to
a temperature higher than the melting point of the polyolefin resin by
from 5 to 25.degree. C. during the lamination, and drawing the laminated
film to form micropores therein, thereby yielding a porous film.