The present invention provides a porous polyolefin film abounding in air permeability and moisture permeability and having extremely high degree of light transmission and tear strength, a process for producing same and intended use thereof. This porous polyolefin film is produced, for example, by stretching an unstretched polyolefin film having a resin composition of 100 parts by weight of polyolefin, 50-150 parts by weight of an inorganic filler having a 50% median diameter of at least 2 &mgr;m but less than 7 &mgr;m measured according to the light-scattering method, and 2-20 parts by weight of a wax of polyolefin series in at least uniaxial direction at an area magnification of 1.1-1.5 times, and possesses physical properties of a water vapor transmission rate of at least 1000 g/m2·24 hrs., a light transmission of at least 65%, and a tear strength of at least 0.6 N.