A heat sealable polypropylene resin laminate film having three or more layers, which comprises a heat sealable layer having a melting point of not more than 150 °C as a surface layer, a substrate layer made of a crystalline polypropylene resin, and an intermediate layer between the heat sealable layer and the substrate layer, wherein the intermediate layer comprises 10-70 % by mass of an α-olefin copolymer containing a cold xylene-soluble fraction in a proportion of not more than 3 % by mass; wherein the heat sealable layer comprises a propylene-butene copolymer in a proportion of not less than 65 % by mass; wherein the thicknesses of the substrate layer and the intermediate layer satisfy the following relational formula: 2 x < y wherein x is the thickness of the substrate layer and y is the thickness of the intermediate layer; wherein the film shows a product of the tensile modulus of elasticity in the machine direction of the film and in the direction transverse to the machine direction of the film of 3.1-6.0 (GPa) 2 as measured according to JIS-K-7127; and wherein the film shows a heat sealing strength of not less than 8 N/15 mm in each of the machine direction of the film and the direction transverse to the machine direction of the film as measured as follows: a sample is cut out from the film in such a manner that the machine direction of the film is the length direction of a bag which was heat sealed (seal width: 10 mm) to form a center press seal bag having a T-shaped sectional sealed part of the bag (central principal rafter seal shape) sized 185 mm·255 mm, wherein the heat sealing was performed under the conditions of a seal temperature of 150 °C, a pressure of 196 kPa (2 kg/cm 2), and a heat sealing time of 2 sec, and a test piece (width 15 mm, length 50 mm) was cut out from a sealed part parallel to each of the length direction and width direction of the obtained bag, and then the test piece was left standing in an atmosphere of temperature 20 °C, humidity 65 % RH for 24 hr, and the strength by peeling at 180 degrees at a distance between chucks of 20 mm (held at 10 mm from heat sealed part) and a speed of 200 mm/min (chart speed 200 mm/min) was measured and taken as a heat sealing strength (N/15 mm); and wherein the film shows a heat sealing energy of not less than 11 N·cm/15 mm in each direction, which is shown by the area surrounded by the curve showing the heat sealing strength and the distance of movement in each measurement chart of the heat sealing strength. a sample is cut out from the film in such a manner that the machine direction of the film is the length direction of a bag which was heat sealed (seal width: 10 mm) to form a center press seal bag having a T-shaped sectional sealed part of the bag (central principal rafter seal shape) sized 185 mm·255 mm, wherein the heat sealing was performed under the conditions of a seal temperature of 150 °C, a pressure of 196 kPa (2 kg/cm 2), and a heat sealing time of 2 sec, and a test piece (width 15 mm, length 50 mm) was cut out from a sealed part parallel to each of the length direction and width direction of the obtained bag, and then the test piece was left standing in an atmosphere of temperature 20 °C, humidity 65 % RH for 24 hr, and the strength by peeling at 180 degrees at a distance between chucks of 20 mm (held at 10 mm from heat sealed part) and a speed of 200 mm/min (chart speed 200 mm/min) was measured and taken as a heat sealing strength (N/15 mm); and wherein the film shows a heat sealing energy of not less than 11 N·cm/15 mm in each direction, which is shown by the area surrounded by the curve showing the heat sealing strength and the distance of movement in each measurement chart of the heat sealing strength.