A semiconductor integrated circuit device having a fuse-blown type ROM for storing information concerning defective bits for the replacement of defective bits in a semiconductor memory device, etc., with redundant bits. The integrated circuit device comprises fuses for constituting the ROM, pads for supplying a melting current to the fuses, and PN junctions each being formed, for example, by a semiconductor substrate and a diffusion layer formed on the semiconductor substrate. Each of the fuses is melted by applying voltage to a circuit connecting the PN junction, the fuse, and the pad so that the PN junction is forward biased, thereby supplying a large current to the fuse.