An environment friendly and inexpensive gas barrier film that allows a medicine to be clearly visible from outside and prevents erroneous administration is provided. A multichamber bag having a diluting solution chamber 3 jointed to one end side of a medicine-accommodation chamber 1 via a weak sealing part 2 and an unoccupied chamber 5 having an opening part 4 jointed to the other end side of the medicine-accommodation chamber 1 via a weak sealing part 2, wherein the medicine-accommodation chamber 1, the diluting solution chamber 3 and the unoccupied chamber 5 are made of a transparent film material and the outside of the medicine-accommodation chamber 1 is covered with a transparent gas barrier film 6, is provided.