A semiconductor device provided with a plurality of sense circuits, each sense circuit including a pair of MOS transistors such that their sources are commonly connected, and that the drain of one transistor and the gate of the other transistor are cross-coupled each other to, thus, sense a difference between potentials applied to the respective gates. The paired transistors respectively include one transistor regions, and are disposed with their source regions being shared among the plurality of sense circuits. These sense circuits are disposed in a manner to share the source regions of the respective transistors. When elimination of only isolation between sense circuits meets with a required miniaturization of the device, paired transistors constituting sense circuits may include two transistor regions or more connected in parallel, respectively.