PURPOSE: To produce a blown bottle free from pinholes at the bottom joint part by a method wherein a tubular material in a molten stage is enclosed in a pair of split molds and pressurized air is blown into the inside of the tubular material to form a closed-end parison, which is then blow molded.

CONSTITUTION: A multilayer plastic tubular body 7 extruded through an extrusion die 6 and being in the molten state is enclosed in a pair of split molds 8, and pressurized air is blown into the inside of the closed tubular body, followed by rapid cooling to obtain the closed-end parison 26'. The parison 26' is then placed in a blow mold for blow molding, and blow molding is carried out. Accordingly, a multilayer blown bottle free from pinholes at the bottom joint part can be obtained.