Process for producing hexafluoro-1,3-butadiene

Disclosed is a process for producing hexafluoro-1,3-butadiene, which is used for an etching gas capable of being used in fine processing for semiconductors, safely in industrialization and at low cost economically. Specifically disclosed is a process for producing hexafluoro-1,3-butadiene comprises (1) a step comprising allowing a compound having four carbon atoms each which bonds to an atom selected from the group consisting of a bromine atom, an iodine atom and a chlorine atom, to react with a fluorine gas in the presence of a diluting gas in a gas phase, thereby preparing a mixture containing a product (A), and (2) a step comprising eliminating halogens excluding a fluorine atom with a metal from the product (A) prepared in the step (1) in the presence of a solvent, thereby preparing a mixture containing hexafluoro-1,3-butadiene.