A uniaxially stretched multi-layer laminate film comprising 251 or more layers in which a first layer and a second layer are alternately laminated, wherein the first layer is a layer composed of a polyester containing a 2,6-naphthalene dicarboxylic acid component as a constituent component and having a thickness of 0.01 μm or more and not more than 0.5 μm, and in a uniaxial stretching direction (X direction), an orthogonal direction (Y direction) to the uniaxial stretching direction within a film plane, and a film thickness direction (Z direction), a difference in refractive index between the Y direction and the Z direction of the first layer is 0.1 or more, and the first layer is a layer having a higher refractive index than the second layer; the second layer is a layer composed of a thermoplastic resin as a constituent component and having a thickness of 0.01 μm or more and not more than 0.5 μm, and the thermoplastic resin is a resin having an average refractive index of 1.60 or more and not more than 1. 65 and having negative optical anisotropy or isotropy, and in the case of using the isotropic resin as the thermoplastic resin constituting the second layer, a ratio of an average layer thickness of the first layer to an average layer thickness of the second layer [(average layer thickness of the first layer)/(average layer thickness of the second layer)] is 1.2 or more and not more than 5.0; on the assumption that the film plane is a reflection plane, a polarization component perpendicular to the incidence plane including the Y direction has an average reflectance of 90% or more at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 0 degree and 50 degrees, respectively; and on the assumption that the film plane is a reflection plane, a polarization component parallel to the incidence plane including the Y direction has an average reflectance of not more than 15% at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 0 degree and an average reflectance of 20% or more at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 50 degrees. the first layer is a layer composed of a polyester containing a 2,6-naphthalene dicarboxylic acid component as a constituent component and having a thickness of 0.01 μm or more and not more than 0.5 μm, and in a uniaxial stretching direction (X direction), an orthogonal direction (Y direction) to the uniaxial stretching direction within a film plane, and a film thickness direction (Z direction), a difference in refractive index between the Y direction and the Z direction of the first layer is 0.1 or more, and the first layer is a layer having a higher refractive index than the second layer; the second layer is a layer composed of a thermoplastic resin as a constituent component and having a thickness of 0.01 μm or more and not more than 0.5 μm, and the thermoplastic resin is a resin having an average refractive index of 1.60 or more and not more than 1. 65 and having negative optical anisotropy or isotropy, and in the case of using the isotropic resin as the thermoplastic resin constituting the second layer, a ratio of an average layer thickness of the first layer to an average layer thickness of the second layer [(average layer thickness of the first layer)/(average layer thickness of the second layer)] is 1.2 or more and not more than 5.0; on the assumption that the film plane is a reflection plane, a polarization component perpendicular to the incidence plane including the Y direction has an average reflectance of 90% or more at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 0 degree and 50 degrees, respectively; and on the assumption that the film plane is a reflection plane, a polarization component parallel to the incidence plane including the Y direction has an average reflectance of not more than 15% at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 0 degree and an average reflectance of 20% or more at a wavelength of 400 to 800 nm relative to the incident polarized light at an angle of incidence of 50 degrees.