| abstract |
The present invention provides a biaxially aligned polyester film, which has excellent transparency, is easy to perform secondary processing such as coating or vapor deposition, and can also meet the performance after secondary processing. The biaxially aligned polyester film of the present invention is composed of a polyester resin composition containing particles, and at least one side meets all the following requirements (1) to (3). (1) The number of fine protrusions with a height of less than 3 nm per area of 4×10 -12 m 2 is 250 or more to 600 or less. (2) The number of fine protrusions with a height of 3 nm or more per area of 4×10 -12 m 2 is from 300 to 600. (3) The arithmetic average height Sa is 0.010 μm or more and 0.025 μm or less. |