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