There are provided a dehydration process of a hydrofluorocarbon or hydrochlorofluorocarbon, which can be done by a simple equipment, and a continuous production process of 1,3,3,3-tetrafluoropropene using the dehydration process. The dehydration process of the hydrofluorocarbon or hydrochlorofluorocarbon includes cooling the hydrofluorocarbon or hydrochlorofluorocarbon in gaseous form containing at least water by a heat exchanger, thereby condensing and liquefying the hydrofluorocarbon or hydrochlorofluorocarbon while freezing and solidifying the water. The production method of the 1,3,3,3-tetrafluoropropene includes a first step for fluorinating 1-chloro-3,3,3-trifluoropropene with hydrogen fluoride to obtain a mixture of the 1,3,3,3-tetrafluoropropene, unreacted 1-chloro-3,3,3-trifluoropropene, hydrogen fluoride, hydrogen chloride and by-products, or dehydrofluorinating 1,1,1,3,3-pentafluoropropane to obtain a mixture of the 1,3,3,3-tetrafluoropropene, unreacted 1,1,1,3,3-pentafluoropropane and by-products, a second step for removing the acidic component, a third step for dehydrating the 1,3,3,3-tetrafluoropropene by the above dehydration process, and a fourth step for purifying the 1,3,3,3-tetrafluoropropene by distillation.