In a semiconductor integrated circuit device, arrangement relationship of power source area I/O pads differs between a peripheral portion and a center portion of a gate region of a chip. That is, in two columns and two rows of the peripheral portion of the gate region, VDD area I/O pads connected to a high-voltage power source VDD and GND area I/O pads connected to a ground power source GND are alternately aligned and arranged both in a row direction and in a column direction. Moreover, in the center portion of the gate region, the same VDD area I/O pads or the same GND area I/O pads are successively aligned in the row direction, and the VDD area I/O pads and the GND area I/O pads are alternately aligned and arranged in the column direction.