[Purpose] In order to provide a cold storage medium container that can be smoothly and reliably filled with a cold storage medium to thereby increase productivity. [Solution] In a cold storage medium container 5 constituting a part of a cold storage heat exchanger, peripheral edge portions of a pair of container members 10 and 12 are brazed to each other to form a body of the container 5 having a cold storage medium filling opening 20 at an end thereof, and the body of the container 5 has an inner fin 11 therein and is filled with the cold storage medium through the cold storage medium filling opening 20 therein. Furthermore, in the cold storage medium container, an engagement portion 13 projects toward inside of the body of the container 5 to engage a part of a corrugated end surface at each end of the inner fin 11, to thereby position the inner fin 11 in the body of the container 5, and a gap is disposed between the end surface at each end of the positioned inner fin 11 and an inner wall of the body of the
