A method of manufacturing a plastic container includes adding nano-sized silica particles to a saturated polyester in an amount of 20 ppm to 10% by weight during transesterification or esterification and polycondensing an aromatic dicarboxylic acid and ethylene glycol as starting materials. The silica particles have an average particle diameter of 3 100 nm. The saturated polyester is polyethyleneterephthalate.