PURPOSE: To manufacture a bottle which is superior in heat-resisting properties, by a method wherein polyester containing an electron-beam sensitive crosslinking agent is made into a primary molded article by injecting the same, to which a biaxial orientation blow is applied after the primary molded article has been irradiated with an electron beam.

CONSTITUTION: A primary molded article 1 is molded by injecting polyester resin obtained by adding a 2W10pts.wt. crosslinking agent (for example, triallyl cyanurate) having an electron-beam sensitive unsaturated bond. Said molded article is made to crosslink by irradiating 10W50Mrad of electron radiations to the same by making use of an electron beam accelerator 2 while the molded article is being made to turn on a roller 5. The molded article is molded into a desired bottle shape by applying biaxial orientation blow molding to the same further. As the molded article is made to crosslink, heat-resisting properties is favorable. The titled bottle is suitable for manufacture of a bottle for a seasoning and drink.