The present invention provides a sheet material including at least an inorganic filler other than asbestos, a polycarbodiimide resin, a rubber having a functional group reactive with a carbodiimide group and, as necessary, an organic or inorganic fiber, or such a sheet material wherein the polycarbodiimide resin and the rubber have been reacted with each other at least partially. A process for producing the sheet material includes making into a sheet-shaped material a composition comprising at least an inorganic filler other than asbestos, a polycarbodiimide resin, a rubber having a functional group reactive with a carbodiimide group and, as necessary, an organic or inorganic fiber, and then heating the sheet-shaped material at a temperature not lower than the softening point of said polycarbodiimide resin, or such a process wherein the heating of the sheet-shaped material at said temperature gives rise to at least partial reaction between the polycarbodiimide resin and the rubber. Said sheet material uses no asbestos fiber and yet exhibits excellent flexibility, sealing property, strength, chemical resistance and heat resistance; and can be used as a gasket having excellent resistance particularly to fluorocarbon refrigerants and oils used in the apparatuses using said refrigerants.