A high-density magnetic memory device is provided. The high-density magnetic memory device includes a vertical transistor formed on a substrate; a magnetic memory element formed on the vertical transistor, the magnetic memory element using magnetic materials for storing data; a bit line connected to the transistor via the magnetic memory element; a word line for writing over and across the bit line; and an insulating layer formed between the word line for writing, and the other components below the word line for writing. According to the high-density magnetic memory device, it is possible to fabricate a high-density magnetic memory device with a vertical transistor.