Refrigeration machine

A chiller comprising:

• a refrigeration cycle including a compressor, a condenser, an expander, an evaporator, a pipe that sequentially connects the compressor, the condenser, the expander, and the evaporator, and a discharge pipe;
• and
• an acoustic device including a space formation section that has a first end and a second end, the first end of the space formation section connected to the pipe and in which a space is formed, and a vibration body that is fixed integrally to the second end of the space formation section and has a lower natural frequency than the space formation section,
• wherein the space formation section includes a cylindrical main body section provided at the first end of the space formation section and a lid section provided at the second end of the space formation section,
• wherein the vibration body is fixed integrally to the lid section,
• wherein the vibration body is fixed such that a main surface of the vibration body and a main surface of the lid section are in surface contact,
• wherein the vibration body and the space formation section are each formed of metal, and
• wherein the metal forming the vibration body has a lower Young's modulus than the metal forming the space formation section, and the metal forming the vibration body has a lower density than the metal forming the space formation section.