A refrigerating and freezing device, the refrigerating and freezing device including: a casing, including an inner container, a housing, and a heat preservation layer, wherein a storage space is disposed in the inner container, a storage container is disposed in the storage space, and the storage container has a controlled atmosphere fresh-keeping space therein; and a controlled atmosphere membrane component, configured to allow more oxygen gas in an airflow in a space around the controlled atmosphere membrane component than nitrogen gas in the airflow in the space around the controlled atmosphere membrane component to pass through a controlled atmosphere membrane to enter an oxygen gas-enriched collecting cavity. The storage space is composed of a top cover and a bottom box, a lower surface of the top cover is provided with a concave cavity, and the controlled atmosphere membrane component is disposed in the concave cavity.