PURPOSE: To prevent interference among lead wires and to improve characteristics by reducing parasitic capacitance because parasitic capacitance generating among lead wires has been a main factor for deterioration of the characteristics of a semiconductor device to be used in the high frequency region.

CONSTITUTION: An inner lead wire 4 which is unified with the same material as a mount island 3 is provided between an outward lead wire 1 and an outward lead wire 2. An earth bonding pad 11 on a semiconductor element 6 and the inner lead 4 are connected by a bonding wire 12. As a result, parasitic capacitance between the outward lead wire 1 and the outward lead wire 2 is separated by the earth inner lead wire 4, and parasitic capacitance is reduced.