Abstract: A technique which can improve manufacturing yield and product reliability is provided in a semiconductor device having a triple well structure. An inverter circuit which includes an n-channel type field effect transistor formed in a shallow p-type well and a p-channel type field effect transistor formed in a shallow n-type well, and does not contribute to circuit operations is provided in a deep n-type well formed in a p-type substrate; the shallow p-type well is connected to the substrate using a wiring of a first layer; and the gate electrode of the p-channel type field effect transistor and the gate electrode of the n-channel type field effect transistor are connected to the shallow n-type well using a wiring of an uppermost layer.