To provide a cement board coated with a fluorine-containing polymer coating agent and producible in a good working environment dispensing with the explosion proofing measure of the manufacturing facility.

This coated cemented excelsior board 1 is produced by coating the surface of a cemented excelsior board 2 with a top coating film 4 of a fluorine-containing polymer. The top-coating film 4 is formed by the application of a coating material produced by using an aqueous dispersion of a fluorine- containing polymer, and the aqueous dispersion of the fluorine-containing polymer is produced by the emulsion polymerization of an alkyl acrylate having a 1-18C alkyl group and/or an alkyl methacrylate having a 1-18C alkyl group, an ethylenic unsaturated carboxylic acid monomer and a monomer copolymerizable with the above monomers in an aqueous solvent in the presence of vinylidene fluoride polymer particles.