To provide an inner sealing material for sealing a mouth part having the function for absorbing a water content permeating into the inner part of a container body or the water content originally remaining in a head space, and capable of opening an opening with a small diameter.

The inner sealing material for sealing the mouth part of the container is prepared by laminating a sealing material laminating a composite sheet equipped with at least an aluminum foil layer and a water content absorbing resin layer on a substrate through a releasing layer, and a resealing material having at least an elastic sheet layer. In the sealing material, the composite sheet and the substrate are mutually laminated and stuck together in a discharging hole forming region surrounded by a half cut for a discharging hole penetrating through the composite sheet within a releasing layer region. An adhesive part in the half cut region is formed on the inner face of the lamination of the composite sheet and the substrate within the half cut for the discharging hole. The releasing layer of the releasing region is formed into a dot pattern-like shape with a dot diameter of 0.5-1.5 mm, and an area ratio of 60-90%.