A technical problem is to fully make up for a restricted upper limit to the preform body wall thickness. An object is to provide a bottle which is narrow-mouthed and yet has a substantially expanded body. In principle, the bottle may include a mouth opening portion with a bore diameter of 10 mm or less and a maximum diameter of the body is 2.5 times or more than the bore diameter of the mouth opening portion, and wherein a maximum diameter portion of the body has a minimum wall thickness of 0.45 mm or more.