A semiconductor device includes cell areas laid out along a periphery of the device. A plurality of transistors are formed in each cell area, and are separated into at least three transistor groups arranged in a direction perpendicular to a circumferential direction of the semiconductor device. Each transistor group is connected to a high-potential power supply or a low-potential power supply. The semiconductor device has at least one interconnection line common to both the transistor group connected to the high-potential power supply and the transistor group connected to the low-potential power supply. The interconnection line serves to connect those transistor groups to external pads.