An ultra-low temperature freezer includes: an insulated case defining a storage compartment having an opening in an upper face; an insulated door capable of opening and closing the opening; a first refrigeration unit configured such that a first compressor, a first condenser, and a first decompressor are mounted on a first mounting board; a second refrigeration unit configured such that a second compressor, a second condenser, and a second decompressor are mounted on a second mounting board; a machinery compartment provided near the insulated case, and configured to house the first and second refrigeration units to be independently drawable in the horizontal direction; and a control unit, where a control circuit is mounted, configured to be drawable independently of the first and second refrigeration units, the first and second refrigeration units and the control unit being housed in the machinery compartment to be stacked in a vertical direction.