A method of fixing a flexible electrical conductor, in which a plurality of flat conductors in which their connecting ends to be connected to another circuit are exposed are integrally covered with a resin-made cladding member, to a fixing portion for connection to the other circuit, comprises the steps of: placing the cladding member on this side of the connecting ends on the fixing portion; and welding together the cladding member on this side of the connecting ends and the fixing portion so as to fix the flexible electrical conductor to the fixing portion. As a result, even if an external force is applied to the flexible electrical conductor, the force is not applied directly to a connecting portion for connecting the connecting ends to connecting ends of the other circuit, thereby improving the electrical reliability in the connection.