When an integrated circuit having an interlayer insulation film built up on top of a wiring layer is subjected to a heat treatment, it is unlikely that a void formed in the interlayer insulation film will rupture in a portion wherein are connected a narrow gap between wirings and a wide open part contiguous therewith. A corner part of a wiring positioned at a portion where a gap and an open part are connected is chamfered, and an end part of the gap is shaped so as to widen toward the open part. Providing the widening end part in the gap thus mitigates any discontinuity in the built up interlayer insulation film between the gap and the open part. As a result, the interlayer insulation film does not readily seal off an end of a void formed in the gap.