The unique properties of diamond like carbon (DLC) film, including its chemical inertness and impermeability, make it possible for new applications in food and beverage. In this paper, I summarize and review the recent progress of gas barrier enhancement of polyethylene terephthalate (PET) bottles for beverage from the view point of the application of DLC coating. A unique technique of plasma CVD method has been developed to deposit DLC layer on the inside surface of PET bottles. The DLC-coated PET bottle exhibits extremely high gas barrier properties against oxygen, carbon dioxide and flavors compared to conventional bottles. For the practical use of PET bottles as a commodity, machines have been introduced for soft drink, wine, Japanese sake, edible oil, seasonings and others.