A semiconductor device permitting the reduction of cost is disclosed. In a semiconductor package wherein electrode pads of a semiconductor chip and corresponding inner leads are electrically coupled with each other through a plurality of bonding wires, sensing wires (second and fourth bonding wires) are made thinner than other bonding wires (first and third bonding wires) coupled to inner leads same as those with the sensing wires coupled thereto, thereby reducing the cost of gold wires to attain the reduction in cost of the semiconductor package.