According to a method of the present invention for treating a terminal portion of an interior part for a vehicle, the terminal portion is stably maintained in a folded state by being welded firmly and deformation is constrained.
In a heating step, in a state where distal end edges of heat shield panels 30A and 30B are abutted against a boundary between a terminal portion 4 and an adjacent portion 5 of a peripheral edge portion 3 of an opening of a roof trim 1 for a sunroof, hot-air is provided toward a back surface of the terminal portion 4 from hot-air nozzles 40A and 40B, thereby softening the terminal portion 4 and melting the back surface of the terminal portion 4. In a folding-back step, the terminal portion 4 is folded back by pressing members 50A and 50B at the distal end edges of the heat shield panels 30A and 30B and then pressed against the adjacent portion 5, thereby welding the back surface of the terminal portion 4 to a back surface of the adjacent portion 5. A ventilation opening 32a is formed in the heat shield panel 30A disposed at a corner portion. In the heating step, a portion of the hot-air from the hot-air nozzle 40A is guided to the adjacent portion 5 through the ventilation opening 32a to heat the adjacent portion 5.