To prevent a stirrer from deforming even in the case of especially a reaction using liquid hydrogen fluoride containing water at the time of the reaction by composing the stirrer of a carbonaceous material when producing a fluorine-containing compound in a vessel equipped with the stirrer.

A stirrer composed of a carbonaceous material is used when producing a fluorine-containing compound in a reactional vessel equipped with the stirrer. A carbon-fiber reinforced plastic (CFP) or a carbon-fiber reinforced carbon (CFC) is preferred as the carbonaceous material. The carbonaceous material preferably has 100-800N/mm2 bending strength, 25,000-13,000N/mm2 tensile elastic modulus, 0.3-1N/mm2 tensile strength and 1.55-1.6h/cm3 density. The diameter of the carbon fibers in the carbonaceous material is preferably 5-15μm. The reactional vessel is preferably composed of the carbonaceous material or lined therewith. Furthermore, the stirrer and the reactional vessel are preferably sealed with a phenol-formaldehyde resin, etc.