Glass tube processing apparatus

A glass tube processing apparatus comprising:

• a heating furnace including a heating element annularly enclosing the circumference of a substrate glass tube which is a heated object, the heating element having a void part passing through the inner circumference side and the outer circumference side of the heating element,
• movement means for relatively moving the substrate glass tube and the heating furnace in a longitudinal direction of the substrate glass tube,
• a temperature measuring device which is provided outside the heating element and is for measuring a temperature of an external surface of the substrate glass tube through the void part, and
• heat generation amount adjusting means for adjusting the amount of heat generation of the heating element, wherein:
• the heating furnace is an induction furnace comprising an induction coil surrounding the circumference of the heating element,
• the void part is a plurality of holes which are formed and arranged not to align in any of the same circumferential direction or the same longitudinal direction of the heating element,
• an opening area of the inner circumference side per one hole of the holes arranged inside the induction coil is 1000 mm2 or less, and
• the total opening area of the inner circumference side of the holes arranged inside the induction coil is 50% or less an area of the inner circumference side of the heating element located inside the induction coil.