A polyolefin-based resin film containing (a) 90 to 97 parts by weight of at least one polyolefin-based resin selected from a propylene-ethylene block copolymer and a propylene-α olefin random copolymer and (b) 3 to 10 parts by weight of an ethylene-propylene copolymer elastomer, wherein the propylene-α olefin random copolymer is present in an amount of 0 to 50% by weight relative to the total amount of the propylene-ethylene block copolymer and the propylene-α olefin random copolymer, and the polyolefin-based resin film has a thermal shrinkage ratio in a longitudinal direction of 3% or more and 20% or less, a thermal shrinkage ratio in a rectangular direction to a width direction of 1% or less, and a yield stress in the longitudinal direction of 150 MPa or more and 250 MPa or less.