an inner closure cap , adapted to be tightly fitted to an open end of a neck portion of a container and covered with an outer closure cap engageable with the outer periphery of the neck portion , includes a cap body having a pouring hole and an upper surface and a sealing member for hermetically closing the pouring hole . the upper surface and the sealing member are formed with respective rings having vertical sides , and the sealing member is adhered to the upper surface with the rings being fitted therebetween in adhesion .