The objective of the present invention is to provide a suitable method capable of reliably joining a cup and a lid when manufacturing a product in which an opening portion of a cup containing contents is sealed using a lid. To this end, in the method of manufacturing an enclosing container according to the present invention: a lid for covering a cup containing contents is formed from a sheet, which is the material of the lid for sealing an opening portion of the cup, and which is provided in advance with an adhesive layer on a side thereof that is to form an inner surface in intimate contact with an outer surface of a peripheral wall of the cup； and an inner surface of a peripheral wall of the lid is caused to adhere to the outer surface of the peripheral wall of the cup.[課題] 提供一種，將收納有內容物之封杯的開口部以蓋予以密封而製造產品之際，可確實地接合封杯與蓋的合適的方法。 [解決手段] 在本發明所述之封裝容器的製造方法中，係從將已收納有內容物之封杯的開口部加以密封所需之蓋的材料，且為在對封杯的周壁的外面做密接的作為內面之一側預先設有接著層的薄片，來形成覆蓋封杯的蓋，同時，將前記蓋的周壁的內面對前記封杯的周壁的外面做接著。
