The gasket material that is manufactured from a joint seat which includes three layers, that is, a front surface layer (1a), a back surface layer (1b) and the middle layer (1c), and these layers have different composition of reinforced fiber and filler respectively, and this joint seat is made from an ingredient made by mixing and kneading rubber, reinforced fiber and filler, then pressurized laminating and vulcanizing the ingredient, this joint seat is characterized in that the reinforced fiber is as a sort of fibril which is composed from one or both of organic fiber and non-asbestos type inorganic fiber, and at least a part of the filler is spicular inorganic fiber and its composition is 10 wt %-45 wt %. According to this joint seat (1), a crack breakage of the gasket that the ingredient material is the joint seat (1) due to fretting is prevented.