NOVELTY - A back surface protective film (1) is laminated film having layer (A) (11) containing infrared ray permeation colorant mixture and rubber-containing aromatic vinyl-type resin, and layer (B) (12) containing film comprising white-colored coloring agent. When film contained in layer (B) is maintained at 135 degrees C for 30 minutes, the change rate of dimension before and after maintaining is plus minus 0.5% or less. When light having wavelength of 740 nm is radiated to surface at side of layer (A) of laminated film, the reflectance with respect to the light is 20% or more.    USE - Back surface protective film is used for solar cell module (claimed) for mounting on roof of residence and buildings.    ADVANTAGE - The back surface protective film has excellent adhesiveness with filler portion containing ethylene-vinyl acetate copolymer, workability, handling property, weather resistance, shape stability and designability. The solar cell module formed using back surface protective film has excellent dark-color external appearance, photoelectric conversion efficiency, heat resistance, flexibility and flaw resistance, and reduced deformation.    DETAILED DESCRIPTION - A back surface protective film is a laminated film having layer (A) containing infrared ray permeation colorant mixture containing at least two types of coloring agent and rubber-containing aromatic vinyl-type resin, and layer (B) containing film comprising white-colored coloring agent and saturated-polyester resin. When the film contained in layer (B) is maintained at 135 degrees C for 30 minutes, the change rate of dimension before and after maintaining is plus minus 0.5% or less. When the light having wavelength of 740 nm is radiated to the surface at the side of layer (A) of the laminated film, the reflectance with respect to the light is 20% or more.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of back surface protecting film.    Back surface protective film (1)    Layers (11,12)