The polyester is a polyester containing an aromatic dicarboxylic acid component in an amount of 60 mol-% or more based on the whole acid component, and is produced preferably by copolymerization of polymerizable unsaturated double bond-containing dicarboxylic acids and/or glycols in an amount of 0.5 to 20 mol-% based on the whole dicarboxylic acid component or the whole glycol component.