There is provided a sealing apparatus for a cryopreservation bag, with which a sealing treatment of an inlet/outlet of the cryopreservation bag is carried out automatically and anyone can safely and properly carry out the sealing treatment. The sealing apparatus includes: a bag clamping device 56; a laser device 57; and a scanning structure 58 for moving the bag clamping device 56, for example. The bag clamping device 56 includes a fixed pinching block 67, a movable pinching block 69, and a clamp actuator 70. The laser device 57 includes a laser oscillator 104 and a condensing lens 107. The fixed pinching block 67 includes a block base 73, a heat radiator 74, and a heat radiator holder 75. An infrared laser beam is radiated to a sealed portion 55 of the bag to form a seal bead 125 for sealing in a state in which the sealed portion 55 is pinched and fixed by the heat radiator 74 and the movable pinching block 69 and while the bag clamping device 56, for example, is moved by the scanning structure 58.