A semiconductor device that can suppress noise transmission through a seal ring provided between two device regions. The semiconductor device includes a logic unit and an analog unit. The semiconductor device further includes a silicon substrate, an insulating interlayer, a seal ring surrounding the outer periphery of the logic unit composed of a conductive film buried in the insulating interlayer, a well provided on the silicon substrate, and an N well guard ring that blocks conduction of a path from the logic unit, through the seal ring to the analog unit. The N well guard ring is disposed between the seal ring region 106 and the logic unit or the analog unit.