Disclosed is a novel packing for a solar cell module laminator. An object is to solve the problem of durability involved in conventional packings and to stably manufacture a high-quality module over a long period of time. The packing is composed of an olefin based rubber crosslinked with an organic peroxide and allowed to have a Shore A hardness, a dimensional stability, and a compression set each falling within a certain range. The olefin based rubber is suitably an EPDM rubber and/or an EPM rubber and is made possible for achieving extrusion molding.