PURPOSE: To enable bending work of a glass plate with a sharp angle leaving no trace of heater element by fixing a heater filament provided along a bending line of the glass plate to a covering glass plate interposing an adhesive agent.

CONSTITUTION: A heater filament 14 is provided in accompany with a bending line 11 along which a glass plate 10 will be bent with a sharp agnle. A layer of a a parting agent 12 is formed on the bending part of the glass plate 10 contacting with the heater filament 14 so as to prevent generation of trace of the heater filament 14 due to melting and sticking of the filament 14 to the glass plate 10 when electric current is passed through the heater filament 14. A covering glass plate 13 is laid on the glass plate 10 provided with the heater filament 14 along the bending line 11 for bending the glass plate with a desired sharp angle to cover the part of the bending line 11 attended by the haeater filament 14 and to hold down the heater filament 14. Further, an adhesive agent is interposed at least a part between the heater filament 14 and the covering glass 13 to prevent the shift of the position of wiring of the heater filament 14 which may be generated when the heater filament 14 is held down by laying the covering glass plate 13 on the heater filament 14. By this constitution, the heater filament 14 is fixed to the glass plate 10.