Provided is a cryopreservation bag with which it is possible to perform the operation for injecting biological tissue into the cryopreservation bag and the operation for degassing the air introduced into the housing part quickly and easily. A housing part 2 for housing biological tissue is demarcated by an outline bead 1 formed at the interface of two sheets S1 and S2 by irradiating two superposed fluorine resin sheets S1 and S2 by an infrared laser beam. A ventilation port 3 continuous with the housing part 2 and an extraction part 4 wider than the ventilation port 3 are formed at one end of the housing part 2, and the extraction part 4 closer to the edge is sealed by a first seal bead 5. The cryopreservation bag is characterized in that a filling port 9 for filling the housing part 2 with biological tissue opens at the other end of the housing part 2.
