In a method for preserving food (30), wherein the food (30) is heated in the moist state in a container (10), which has a venting opening (20) 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 (10) and exits through the venting opening (20), wherein after the heating has ended a gas (G) is injected into the container (10) using a cannula (40), and wherein a container wall made of a plastic film (12) is pierced with the cannula (40), according to the invention the plastic film (12) that is used has a thickness of less than 100 μm, wherein at least one layer of the plastic film (10) is made of polyethylene terephthalate having a thickness of greater than 19 μm.
