PURPOSE: To obtain a heat exchanger in which a structure with various shelves stacked can be obtained without applying a stress to a rod structure firmly attached to coils by applying a prescribed twist to the tubular parts of the various coils in a refrigerator or a rack type evaporator of a freezer.

CONSTITUTION: A heat exchanger used for a rack type evaporator in a refrigerator or a freezer is constituted of a supporting-heat exchange enhancement structure 4 including a plurality of stacked shelves 2 and forming a support surface substantially parallel to the surface of a coil device above the coil 3 with a tubular body as each coil 3 extending along a path having straight and substantially mutually co-planar parts and alternate bends and metal rods welded to the coil 3. The coil 3 has at least one part 7 disconnected from the supporting-heat exchange enhancement structure 4 with respect to each shelf. The part 7 is substantially parallel to the long and straight part of the coil 3 and extends adjacently to one side of the shelf 2. The part disconnected from the supporting-heat exchange enhancement structure 4 is connected to a tubular part 6 for connecting the coils of two shelves which are not mutually co-planar.