PURPOSE: To carry out bonding work very easily and carry out the bonding work efficiently by providing ground tab bonding sections of step shape to a part of a thermal insulation.

CONSTITUTION: Three cuts 3 are made in parallel in the direction crossing the laminating direction of a part of a laminate thermal insulation 1, and respectively left and right halves are cut in the step shape of exact opposition to provide ground tab bonded sections 6 of step shape. Then, the end of ground tabs 4 are folded back and a conductive bonding agent 5 is applied to an upper surface section. Then, thermal insulations of the ground tab bonded sections 6 on the left and right are placed on said bonding agent applied section, and the proper quantity of the conductive bonding agent 5 to the whole of bonded surfaces of the ground tab bonded sections 6, and further the ground tabs 4 are folded back in a manner to cover the whole of the ground tab bonding sections 6 to complete the bonding work.