A lid member for a food container having a layered structure in which a surface sheet is laid on a composite sheet, said surface sheet including an easily-peelable area that is easily separated from the composite sheet, formed by applying a lubricant between the surface sheet and the composite sheet, said surface sheet including a non-peelable area adjacent to said easily-peelable area; a first slit cut vertical-sectionally through the composite sheet, said first slit defining one or more apertures in said lid to form an opening area in said composite sheet; a second slit in said surface sheet defining a boundary between the easily-peelable area and said non-peelable area of said surface sheet; and said surface sheet being adhered to said composite sheet at said composite sheet opening area over an area that is smaller than said composite sheet opening area.