A semiconductor IC device which includes a circuit region and a peripheral region on a main surface of a semiconductor substrate, a first insulating film formed over the main surface, external terminals arranged in the peripheral region and formed over the first insulating film, a conductive guard ring formed over the first insulating film and provided around the external terminals, and second insulating films formed in the internal region and the peripheral region, the second insulating film in the peripheral region is formed over the first insulating film and over the guard ring and is contacting the external terminals, the second insulating films of the circuit region and that of the peripheral region are separately formed and are isolated from each other. Separate second insulating film may be formed over the wirings of one or more of existing wiring levels of the semiconductor device.