A highly reliable memory device is provided. The memory device includes a first conductor, a second conductor above the first conductor, a third conductor above the second conductor, a fourth conductor above the third conductor, a fifth conductor above the fourth conductor, a sixth conductor above the fifth conductor, a seventh conductor, a first insulator, a second insulator, a first semiconductor, and a second semiconductor. At least third conductor and the fourth conductor have an opening. The first insulator, the first semiconductor, the second insulator, and the second semiconductor are provided in this order on an inner surface of the opening. The seventh conductor is provided between the first semiconductor and the second insulator in a region between the third conductor and the second insulator. The first semiconductor is electrically connected to the second conductor and the fifth conductor. The second semiconductor is electrically connected to the first conductor and the sixth conductor.