Substrate processing apparatus

A substrate processing method comprising a step of processing a substrate using a hot-wall type substrate processing apparatus including:

• a reaction tube body having a first gas introducing section and a gas exhausting section separated by a distance from each other in a first direction, a first plate substantially perpendicular to said first direction and having said first gas introducing section, a second plate and a third plate substantially parallel to a first plane including said first direction and a second direction substantially perpendicular to said first direction;
• and fourth and fifth plates which are substantially parallel to said first direction and are substantially perpendicular to said first plane;
• a heater facing one or both of said second and third plates;
• a substrate holder disposed in said reaction tube body and being capable of holding the substrate within said reaction tube body between said first gas introducing section and said gas exhausting section in a state where a face of said substrate to be processed is substantially parallel to said first plane;
• and
• a gas heating tube provided along one or both of said fourth plate and said fifth plate, and having a second gas introducing section and a gas discharging section which is in communication with said gas introducing section.