There is provided a structure for connecting a flat cable to bus bars. To this end, conductor strips are first exposed from the end portion of the flat cable. The inventive structure includes bus bars and conductor strips adhered to the bus bars, thereby forming a joint section including strip layers and strip gaps. The structure includes a first and a second insulator resin sheet respectively placed on a first and a second face of the joint section. At least the first insulator resin sheet is then configured such that it penetrates into the strip gaps and adheres to the second insulator resin sheet, so as to form insulating grooves. In this manner, narrow conductor strips of a flat cable and corresponding bus bars can be connected with sufficient mechanical strength, and their insulation is improved.