To minimize the deformation of a plastic vessel which is filled with a beverage provided in a heated state.

The plastic vessel is filled with a non-carbonated beverage at ordinary temperatures; carbon dioxide gas is blown into a head space of the plastic vessel filled with the non-carbonated beverage; the carbon dioxide gas is substituted for a part of air in the head space; a mouth of the plastic vessel, in which the carbon dioxide gas is substituted for the part of the air in the head space, is closed with a cap so as to sealed; and the beverage, which is sealed in the plastic vessel, is heated so as to be provided for a consumer.