{HEAD ~ a reaction tube body} provided in {TAIL ~ the heater means}, and having a first gas introducing section and a gas exhausting section separated at a predetermined distance from each other in a predetermined first direction 
provided in
{ HEAD ~ a reaction tube body } provided in { TAIL ~ the heater means } , and having a first gas introducing section and a gas exhausting section separated at a predetermined distance from each other in a predetermined first direction
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH