Provided are a preform and a method for manufacturing a plastic bottle, which enable enlargement of the plastic bottle. The preform 40 includes a mouth 41, a body 50 connected to the mouth 41, and a bottom 60 connected to the body 50. The trunk 50 has a small diameter part 51 located on the mouth 41 side, a large diameter part 53 located on the bottom 60 side, and an enlarged diameter part 52 located between the small diameter part 51 and the large diameter part 53 and enlarged in diameter from the small diameter part 51 side toward the large diameter part 53 side. A thickness T4 of the large diameter part 53 is thicker than a thickness T2 of the small diameter part 51. The thickness T3 of the enlarged diameter part 52 is gradually increased from the small diameter part 51 side toward the large diameter...

You do not currently have access to this content.