The present invention provides a process for producing 1,2,3,4-tetrachlorohexafluorobutane having a high purity at a low cost industrially and efficiently. The process for producing 1,2,3,4-tetrachlorohexafluorobutane according to the present invention comprises a step of allowing 1,2,3,4-tetrachlorobutane to react with a fluorine gas to prepare a reaction product containing 1,2,3,4-tetrachlorohexafluorobutane and hydrogen-containing compounds as an impurity, and a step of introducing the reaction product into single or plural distillation columns and distilling to separate the hydrogen-containing compounds from the reaction product and thereby preparing purified 1,2,3,4-tetrachlorohexafluorobutane wherein the at least one of distillation columns has a theoretical plate number of 15 or more.