The present invention provides a method and device fixed on the tray by the treated element when treating the plasm and fore and afters for improving the treatability and operationality, and delaminating the substrate from trays easily when necessary. Installing the substrate installed on the tray onto the support platform, cementing the tray and substrate using a heat strip delaminating cementing element in a plasma processing method processing the surface of substrate by palsms. Using a foarming delaminating sheet befittingly as a heat delaminating cementing element. Because the heat delaminating cementing element usually provided with cementing character, the tray and substrate fixed earnestly before and after the plasm treating, thereby obtaining a well operationality. Alternately, heating the tray to the temperature above the tated delaminating temperature after treating, so delaminating the substrate from tray easily.