First and second memory cell arrays each having memory cells arranged in the X and Y directions lie side by side in the Y direction with space between them. A relay buffer is provided between first and second row decoders for buffering a control signal to be supplied to the second row decoder. An inter-array block between the first and second memory cell arrays is constituted by at least either a tap cell or a dummy memory cell. The relay buffer and the inter-array block are the same in position and size in the Y direction.