SEMICONDUCTOR DEVICE

A semiconductor device in which noise is reduced without an increase in chip area. The device is used as an MRAM in which a memory mat is formed on a silicon substrate surface and the central area of the memory mat is used as a memory array and the area around the memory array is used as a dummy memory array. In the dummy memory array, a capacitor is formed between each bit line, each digit line and a supply voltage line, and a grounding voltage line. Therefore the peak value of a current flowing in each of the bit lines, digit lines and supply voltage line is decreased.