TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: A corrugation is provided in the surface of the polyester film, as the corrugation at the interface. The hard-coat surface shape of the convex portion of the corrugation in the cross-sectional direction is a concave portion or convex portion. Corrugation of hard-coat layer is not formed by particles in the hard-coat layer and polyester film. The hard-coat film has a thermal contraction rate of 0.8% or less in direction(s) when processed at 150degrees C for 30 minutes. The average value of arithmetic mean inclinations of two ways in which the surface of hard-coat layer orthogonally crosses is 0.2-1degrees . The pointedness of surface height distribution of the hard-coat layer is 1.5-3, and the haze of the hard-coat film is less than 3%. Preferred Composition: The polyester film contains a UV absorber. Preferred Film: A reflection-prevention film is obtained by forming a low-refractive-index layer having a refractive index of 1.45 or less or a high-refractive-index layer having a refractive index of 1.55 or more, on the hard-coat layer of the hard-coat film. The film has a transmittance of 5% or less at a wavelength of 380 nm, and a haze of less than 4%. Preferred Method: Relaxation-processing is further carried out at 1.5-15% in the longitudinal and/or width direction at 200-240degrees C, after relaxation processing at 3-7%. EXAMPLE - A hard-coat agent containing (in wt.%) mixture (70) of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate and, Aronix M-350 (RTM: trimethylolpropane ethylene-oxide-modified triacrylate) (10), Cymel 303 (RTM: fully-alkylated melamine) (20), catalyst (1 weight part), and leveling agent (0.2 weight parts), and having a viscosity of 2000 mPa.second at 25degrees C was applied on a polyethylene-terephthalate film. The film was extended after pre-heating at 70degrees C for 15 seconds, and fine-extended 1.2 times in the width direction at 75degrees C. The film was then extended 3.3 times in the width direction at 95degrees C, heat-processed for 25 seconds, and relaxation-processed at 5% to form a hard-coat layer. The obtained hard-coat film had a thickness of 5 mu m. The hard-coat surface and polyethylene-terephthalate film surface had corrugations. The arithmetic average roughness was 41 nm and the pointedness of surface height distribution was 2.2. The hard-coat film had excellent abrasion resistance, and formed reflection-prevention films having excellent visibility and no coloring non-uniformity.