A semiconductor device which uses a semiconductor element having main current input/output electrodes, one and the other of which are extended up to a one surface and a remaining surface of a semiconductor chip respectively for causing one of the input/output electrodes to be contacted with a conductive layer of a insulating substrate, whereby the semiconductor element is supported on or above the insulating substrate. A conductive strip which is made of a composite material of carbon and aluminum or a composite material of carbon and copper is used for connection between the remaining input/output electrode of the semiconductor chip and the conductive layer of the insulating substrate.