Abstract: A container for a product to be heated or cooked in an oven such as a microwave oven, whose lid comprises an upper sub-assembly (I) with a metal layer and a lower sub-assembly (II) comprising an upper heat reactivatable layer (4) affixed initially so as not to adhere against the metal layer (3) and a lower heat sealing layer (5) sealed against the peripheral flange (1). The heat reactivatable layer (4) and the heat sealing layer (5) are layers of a synthetic material which can be peeled respectively off the metal layer (3) and the peripheral flange (1). In addition the heat reactivatable layer (4) has, vertically in line with the peripheral flange (1) a peripheral portion (6) adhering to the metal layer (3) following heating thereof during sealing of the heat sealing layer (5) on the peripheral flange (1).