| abstract |
A polyester film has a maximum surface height on a surface A side (SRmaxA) of 1500 nm to 7000 nm, a maximum surface height on a surface B side (SRmaxB) of 5 nm or more but less than 7000 nm, the SRmaxA and the SRmaxB satisfying the following relation (1), and a strength at break at 25° C. of 200 MPa to 330 MPa in both the longitudinal direction and the width direction. n SR max A>SR max B (1) |