PURPOSE: To reduce the area of a collecting section combining both ends of a plurality of hot wire wired to window glass, and to improve the visual range by thickening the collecting section toward a connector for supplying a power supply mounted to the collecting section.

CONSTITUTION: A plurality of the hot wires 4 are wired in parallel with the window glass 1, and both ends of each hot wire 4 are combined by the collecting sections 2, 3. The connectors 5, 6 for supplying the power supply are set up at the central sections of the collecting sections 2, 3. The collecting sections 2, 3 are thickened substantially toward the central sections. When currents enter from the connector 5, currents are distributed to each hot wire 4 through the central section 2a of the collecting section 2 and upper and lower terminal sections 2b1, 2b2, 2c1, 2c2 while currents reach the connector 6 through each terminal section from the collecting section 3, and several hot wire 4 is heat-generated. Since the collecting sections 2, 3 are thickened toward the connector 5, 6 sections at that time, the areas are small, and the backward visual range is improved.