To provide a valve provided with friction resistant, chemical-resistant, heat-resistant and creep resistant properties and enlarging a temperature range exhibiting creep resistant property, thereby outstandingly enhancing sealing performance without impairing the creep resistant property.

In the valve, valve sealing material such as a packing 8 for sealing a motion part of a valve structure body or a gasket 13 for sealing a fixed part is attached to air-tightly seal the part. In the valve, the valve sealing material is a molded article for valve attachment in which 5-30% carbon fiber and 5-30% carbon black in weight percent are mixed respectively into a resin mixture comprising polytetrafluoroethylene and a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer and containing 3-15% tetrafluoroethylene-perfluoroalkylvinyl ether copolymer in weight percent.