A lower electrode (22) is provided on a semiconductor chip substrate (26). A lower electrode (22) is covered with a first interlayer insulating layer (27) from above. A first contact hole (28) is provided on the lower electrode (22) to penetrate through the first interlayer insulating layer (27). A low-resistance layer (29) forming the resistance variable layer (24) is embedded to fill the first contact hole (28). A high-resistance layer (30) is provided on the first interlayer insulating layer (27) and the low-resistance layer (29). The resistance variable layer (24) is formed by a multi-layer resistance layer including a single layer of the high-resistance layer (30) and a single layer of the low-resistance layer (29). The low-resistance layer (29) forming the memory portion (25) is isolated from at least its adjacent memory portion (25).