A gasket provided with a sliding-treated layer on the surface of a fluorine rubber gasket body. The sliding-treated layer is a baked coated film of a sliding treating agent. The sliding treating agent is an aqueous emulsion containing a solid lubricant, an urethane-based resin as a matrix, and a reactive group-coupled alkyltrialkoxysilane series compound represented by the following chemical formula as an adherability modifier.

{wherein X (reactive group) is an amino-containing group or an epoxy-containing group, n is a natural number of 2 to 4, and R is an alkyl group having a carbon number of 1 to 3}.