PURPOSE: To reduce the cost by heating and softening the desired bends and fixing a coil at the deformed bends, after inserting the coil in a straight line of glass pipe, when a filament coil is inserted in a glass pipe with plural bends to make into an infrared-ray heater.

CONSTITUTION: In a transparent, opaque, or colored opaque straight quartz glass pipe 1, a tungsten filament coil 2 is inserted placing a clearance of total 0.8∼2.2mm to the inner surface of the pipe 1, an inert gas is sealed there making the sealing pressure at 0.45∼0.75atm at the normal temperature, and both ends of the pipe are sealed with bases 6 which have an outer lead wire 4 and a lead wire 6 respectively. After that, the pipe 1 is bent to make bends 3 and straight lines 7, and when the bends 3 are formed, the parts are heated by a gas burner, a high-frequency wave, a laser, or the like, to deform the position in an oval form, and the coil 2 at the inside is fixed. By such a constitution, it is not necessary to bend the pipe beforehand, and the formation is made easier.