A transparent polyester film having excellent antistatic properties, which are little effected with variation of the humidity, and further having excellent flexing resistance, pinhole resistance and printability, which is made from a mixture comprising (i) a polyester consisting essentially of a residue of dibasic acids wherein at least 80% by mol is terephthalic acid and a residue of at least one glycol and (ii) a block copolyester consisting of a crystalline polyester segment having a high melting point and a soft polymer segment having a low melting point and a number average molecular weight of 400 to 8,000, said soft polymer segment having a low melting point being contained in an amount of 0.5 to 10% by weight on the basis of the whole weight of the components (i) and (ii), and (iii) a sulfonic and/or phosphoric acid metal salt having a good heat resistance, and which is produced by melt-extruding the mixture of the components (i), (ii) and (iii), drawing at least uniaxially and then heat-treating the resultant at a temperature of 170.degree. C. or higher and lower than the melting point of the polyester (i).