A synthetic-resin barrel for a syringe has an injection needle fixed to an open distal-end portion thereof or a distal-end portion thereof and is sterilized by radioactive rays or electron beams. The synthetic resin forming the barrel contains a phenol-based antioxidant. The amount of phenoxyl radicals of the synthetic resin measured by the electron spin resonance apparatus is 0.1 to 1.0×1012 spins/mg.
