To make it possible to produce liquid crystal panels having high group accuracy at a good yield, to improve durability and to maintain a high yield in spite of repetitive use by constituting a sealing sheet of a silicone rubber layer or fluororubber layer and polyimide layers disposed on both surfaces of the rubber layer.

This sealing sheet consists of the three-layered structure provided with the silicone rubber layer or the fluororubber layer (rubber layer) and the polyimide layers 3, 4 disposed on both surfaces thereof. If both surfaces of the rubber layer are provided with the polyimide layers 3, 4 in such a manner, there is no limitation on the number of these layers. While the thicknesses of the rubber layer 1 and the polyimide layers 3, 4 are not particularly limited, the thicknesses are so set that the former usually attains about 5 to 500μm and the latter attains about 5 to 200μm. The rubber layer 1 compounded with proper amts. of additives, such as aging preventive agents, fillers and crosslinking agents, may be preferable. The products having the high gap accuracy are produced at the good yield in such a manner.