A method for manufacturing a resin container includes: performing injection molding on a resin preform; adjusting a temperature of the preform manufactured in the performing injection molding; and performing blow molding on the temperature-adjusted preform to manufacture the resin container. In the performing injection molding, injection molds are opened after completion of filling and pressure holding of a resin material, and the preform is taken out without being cooled in the injection molds after the completion of filling and pressure holding. In addition, in the adjusting the temperature, a refrigerant is introduced into the preform to cool the preform.