Abstract: A container that may be closed all around is useful for deepfreezing suspensions of living cellular materials kept in elastic bags. The container has two plane-parallel thin-walled metallic plates (14, 16) secured in swivellingly interconnected frame halves (20, 22). When the frame halves (20, 22) are superimposed, the plates (14, 16) secured therein are arranged with parallel faces at a slight defined distance from each other and form an intermediate cavity (12) in which the bag is placed. When the container is closed, the plates (14, 16) press the bag arranged inside (12) the container and flatten it until it has a small defined thickness. A microporous layer (30) that considerably increases heat transfer to the coolant that surrounds the container is secured to the outer side of plates (14, 16) by an adhesive layer. Furthermore, since the homogeneously flattened bag has a high surface/volume ratio and is pressed until it has no folds or bulges, the cellular material may be quickly and controllably cooled.