Abstract: Packaging for foodstuffs comprising a device for automatic closure at the end of cooking. The automatic closure device (15) comprises a first chamber (38) communicating with the outside and enclosing a valve and second chamber (40) communicating with the first chamber and enclosing a block of thermofusible material, such second chamber communicating with the interior of the packaging by a channel of small cross section (41). During cooking, the gases can leave freely from the packaging and, at the onset of cooling, the valve prevents air from penetrating the packaging while the thermofusible material solidifies in the channel of small cross section.