A method for preparing a compound containing fluorine.

A method for producing a fluorine-containing compound, which comprises reacting the following compound (1) with the following compound (2) to produce the following compound (3) (provided that the compound (3) is a compound having a content fluorine of at least 30 mass% and has a hydrogen atom or an unsaturated bond which can be fluorinated), fluorinating the compound (3) in a liquid phase to produce the following compound (4), followed by reaction of cleavage EF compound (4) to obtain a compound (5) and / or a compound (6): (See compounds) wherein RA, RB: RA is a bivalent organic group containing fluorine is the same as R AF, or a divalent organic group which becomes R AF by a fluorination reaction, and RB is a monovalent organic group which is the same as R BF, or a monovalent organic group which becomes R BF by a fluorination reaction, R AF, R BF: R AF is an organic group bi valent fluorine-containing is the same or different from RA, and when different, is a group having RA fluorinated, and R BF is a monovalent organic group containing fluorine which is the same or different from RB, and when different is a group having RB fluorinated, E 1, E 2: reactive groups which react together to form a bivalent connector (E) group, E: a bivalent connecting group formed by the reaction of E 1 and E 2, EF: a group is the same as E, or a group having E fluorinated, provided that at least one selected from R AF, R BF and EF is a group formed by a fluorination reaction, and E F1, E F2: are each is independently a group formed by cleavage of EF.