PURPOSE: To extremely reduce the power supply noise of an amplifier and, at the same time, to stabilize the operation of a digital-analog mixed integrated circuit by forming a capacitor of the first and second metallic wiring layers facing each other with an interlayer insulating film in between.

CONSTITUTION: A capacitor is formed by facing the first and second metallic wiring layers 2 and 3 with an interlayer insulating film in between. When the capacitor is formed in such way, high-frequency digital noise superimposed upon a power supply voltage line is by-passed from a VDD (positive voltage) to a VSS (negative voltage), because an electrostatic capacity is formed between the VDD and VSS, and the capacitor is formed to the power supply line of an amplifier. Therefore, a measure can be taken against the noise of the amplifier by the conventional two metallic layer wiring technique without changing its process.