Abstract: Apparatus for cooling and deep freezing samples of biological material. The cooling zone, containing the closed plastic vessels with the samples, is enclosed between two parallel, plate-like layered cooling elements. The latter are made of at least two cooling layers containing blocks of Peltier elements, alternating with plates of a heat-conducting metal, preferably aluminium. The disposition with several layers of Peltier elements increases the temperature difference between the inner space and environment. The innermost layer of the cooling elements is a metal plate as well; the outermost layer is a metal plate with means for external cooling, such as channels for circulating water or cooling ribs. The cooling zone is either a metal block with cavities to receive the sample vessels or simply the free space between the two innermost plates of the cooling elements, into which the vessels can be inserted.