A continuous heating furnace (200) and stretched out long in the endless shape arranged transfer body 210 for conveying the accused hydrous product, and the furnace body 212 that surrounds all or a part of the transfer body to form a baking space, from the furnace body and a roller (214) for supporting a portion of the transfer body. A continuous heating furnace (200) is heated by the fuel gas to the combustion in the inlet hole, the exhaust gas or the combustion chamber to the fuel gas distribution chamber, the lead-out portion which exhaust gas is guided, parts derived for combustion to flow into the heater main body accused Dangerous copy to heat the radiation surface and having an exhaust hole for exhausting the heated exhaust gas out of the heater unit to copy surface, no cost to one or more of the enclosed gas heater disposed in the body, communicating exhaust ball and the closed gas heater, and further comprises a pipe 216 for an exhaust that is exhaust gas is guided. Further, the pipe for exhaust can be the heat exchange between the exhaust gas and the distribution roller to the pipe for the exhaust.