We have developed a new technique of chemical recycling for polyethylene terephthalate (PET), which can depolymerize PET to terephthatic acid(TPA) and ethylene glycol(EG) using water at high temperature. This method uses no any hazardous material, and is a promising environmentally-friendly chemical recycling process. The process is expected to be an economical compact process in combination with the present collection system for used PET bottles in Japan.