An object of the present invention is to provide a method for producing a fluorinated organic compound, whereby an iodosylbenzene derivative can be easily separated and recovered. The above object can be achieved by a method for producing a fluorinated organic compound, comprising step A of fluorinating an organic compound (1) by reaction with a fluorine source (3) in the presence of a hypervalent iodine aromatic ring compound (2a), or in the presence of an iodine aromatic ring compound (2b) and an oxidant (2bo); wherein the fluorine source (3) is a fluorine source (3a) represented by formula: MFn, wherein M is H, a metal of Group 1 of the periodic table, or a metal of Group 2 of the periodic table; and n is 1 or 2; and step B of separating the iodine aromatic ring compound from a reaction liquid after step A is started.