Patent ID: 8434637

Claim:
A packaging bag for microwave oven heating: which is manufactured by using a complex film at least one side of which comprises a sealant layer, folding the complex film or placing the complex film upon another same complex film so as to encounter the sealant layer of the folded complex film or the sealant layers of the complex film and the another complex film to each other, sealing the peripheral of overlapped parts of the complex film or the peripheral of overlapped complex films by a main seal part to form a sealed bag, and providing in the bag a region which is isolated from a space for storing contents by a steam port seal part, wherein the steam port seal part is formed consecutively from the main seal part or is formed as a part independent of the main seal part, and wherein the steam port seal part surrounds a steam easy permeable means, wherein the lamination strength between the layers of the complex film in hot condition is in the range of 1.5 N/15 mm in width to 5 N/15 mm in width or at the level of the material destruction of the film, and the seal strength at least at the steam port seal part in hot condition is in the range of 5 N/15 mm in width to 28 N/15 mm in width.