This process for producing fluorine-containing compounds includes liquid-phase fluorination by introducing a raw material compound and fluorine gas into a solvent to replace hydrogen atoms in the raw material compound with fluorine atoms. More specifically, the process for producing fluorine-containing compounds includes (1) promoting fluorination by dissolving the raw material compound in anhydrous hydrofluoric acid and introducing into a liquid-phase fluorination solvent, or (2) promoting fluorination by dissolving the raw material compound in a perfluoro compound having a plurality of polar groups in a molecule thereof and introducing into a liquid-phase fluorination solvent. According to these processes, a fluorination reaction can be carried out at high yield and without containing hardly any isomers while using a hydrocarbon compound as is for the raw material.