Abstract: A method for preserving food. The food is heated in a moist state in a container, which has a venting opening and is suited as transport and retail packaging, by way of microwaves (M) for a limited time, however at least until hot steam (D) forms in the container and exits through the venting opening. After the heating has ended, a gas (G) is injected into the container using a cannula, and a container wall made of a plastic film is pierced with the cannula. The plastic film that is used has a thickness of less than 100 ?m. At least one layer of the plastic film is made of polyethylene terephthalate having a thickness of greater than 19 ?m.