PURPOSE: To connect floor materials integrally with each other electrically by filling a conductive welding material on which conductive coated layer is formed intermittently on a welding base material in longitudinal direction directly into the floor materials.

CONSTITUTION: In a conductive welding material 11, a thermoplastic resin-made welding base material 13 is formed in braid or bar shape by extrusion, etc., a conductive coating material formed by combining conductive material with thermoplastic resin is used as a coating in paste sol state or by dispersing or dissolving in a proper solvent, and the material is applied on the surface of the welding base material 13 in a proper method and dried to form a conductive coated layer 15. In this case, the conductive coated layer 15 is formed on the surface of the welding base material 13 so that the formed and non- formed sections of the conductive coated layer 15 appear alternately in longitudinal direction of the base material 13. The conductive welding material 11 thus formed is softened and filled into a clearance between floor tiles to connect them integrally with each other electrically in high welding strength.