The present invention provides a fluorinated compound having functional groups in a high concentration so that adequate characteristics of the functional groups can be obtained and having high transparency in a wide wavelength region, a fluoropolymer, and a process for its production. The present invention provides a fluorinated diene represented by the following formula (1): CF.sub.2.dbd.CFCH.sub.2CH(C(R.sup.1)(R.sup.2)(OH))CH.sub.2CH.dbd.CH.sub.2 (1) wherein each of R.sup.1 and R.sup.2 which are independent of each other, is a fluorine atom or a fluoroalkyl group having at most 5 carbon atoms.