A biaxially oriented polyester film roll formed by winding the biaxially oriented polyester film around a film roll, the biaxially oriented polyester film roll comprising: an antimony content in the biaxially oriented polyester film is 10 ppm or less when measured as set out in paragraphs 83 and 84 of the present description; a phosphorus content in the biaxially oriented polyester film is 25 ppm or more and 75 ppm or less when measured as set out in paragraphs 83 and 85 of the present description; an arithmetic mean roughness of the surface of the biaxially oriented polyester film is 0.02 μm or more and 0.05 μm or less when measured as set out in paragraph 87 of the present description; and the biaxially oriented polyester film roll satisfying the following requirements to: a winding length of the film roll is 8000 m or more and 80000 m or less; a width of the film roll is 500 mm or more and 4000 mm or less; an average hardness is in the range of 500 or more and 700 or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction when measured as set out in paragraph 79 of the present description; a variation in hardness is 10% or more and 20% or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction; a thickness of a polyester film of the polyester film roll is 5 μm or more and 40 μm or less; an irregularity of thickness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average film thickness, is 10% or less at a position where a thickness pattern makes a concave portion in an irregularity of thickness in the width direction on a surface layer of the film roll and at a concave portion that has a maximum thickness difference when measured as set out in paragraph 89 of the present description. an antimony content in the biaxially oriented polyester film is 10 ppm or less when measured as set out in paragraphs 83 and 84 of the present description; a phosphorus content in the biaxially oriented polyester film is 25 ppm or more and 75 ppm or less when measured as set out in paragraphs 83 and 85 of the present description; an arithmetic mean roughness of the surface of the biaxially oriented polyester film is 0.02 μm or more and 0.05 μm or less when measured as set out in paragraph 87 of the present description; and the biaxially oriented polyester film roll satisfying the following requirements to: a winding length of the film roll is 8000 m or more and 80000 m or less; a width of the film roll is 500 mm or more and 4000 mm or less; an average hardness is in the range of 500 or more and 700 or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction when measured as set out in paragraph 79 of the present description; a variation in hardness is 10% or more and 20% or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction; a thickness of a polyester film of the polyester film roll is 5 μm or more and 40 μm or less; an irregularity of thickness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average film thickness, is 10% or less at a position where a thickness pattern makes a concave portion in an irregularity of thickness in the width direction on a surface layer of the film roll and at a concave portion that has a maximum thickness difference when measured as set out in paragraph 89 of the present description. a winding length of the film roll is 8000 m or more and 80000 m or less; a width of the film roll is 500 mm or more and 4000 mm or less; an average hardness is in the range of 500 or more and 700 or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction when measured as set out in paragraph 79 of the present description; a variation in hardness is 10% or more and 20% or less when a hardness of an outermost surface layer of the polyester film roll is measured at an interval of 50 mm along the film width direction; a thickness of a polyester film of the polyester film roll is 5 μm or more and 40 μm or less; an irregularity of thickness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average film thickness, is 10% or less at a position where a thickness pattern makes a concave portion in an irregularity of thickness in the width direction on a surface layer of the film roll and at a concave portion that has a maximum thickness difference when measured as set out in paragraph 89 of the present description.