To provide a heat exchanger for a Stirling refrigerating machine excellent in heat exchange efficiency, pressure durability and refrigeration efficiency and suitable for an air conditioning apparatus adopting air conditioning air as a fluid for heat exchange by providing a relatively large heating surface area.

The inventional aims at adopting a fin-and-flat tube heat exchanger instead of a conventional shell-and-tube type. In a Stirling refrigerating machine by a Stirling cycle where reciprocating motion of a working gas operates refrigeration, the heat exchanger for the Stirling refrigerating machine for performing heat exchange between a working gas and a fluid to be heat exchanged includes a working gas flow route for flowing the working gas, flat tubes 22 having wide width and capable of keeping in contact with the fluid, fins 23 provided on the flat tubes 22, and flanges 25 capable of fixing the flat tubes 22.