The present invention provides a memory structure including a resistance-changing storage element, which enables a reset operation with a reset gate and in which cross-sectional areas of a resistance-changing film and a lower electrode in a current-flowing direction can be decreased. The semiconductor device of the present invention comprises a first pillar-shaped semiconductor layer, a gate insulating film formed around the first pillar-shaped semiconductor layer, a gate electrode made of a metal and formed around the gate insulating film, a gate line made of a metal and connected to the gate electrode, a second gate insulating film formed around an upper portion of the first pillar-shaped semiconductor layer, a first contact made of a second metal and formed around the second gate insulating film, a second contact which is made of a third metal and which connects an upper portion of the first contact to an upper portion of the first pillar-shaped semiconductor layer, a second diffusion layer formed in a lower portion of the first pillar-shaped semiconductor layer, a pillar-shaped insulating layer formed on the second contact, a resistance-changing film formed around an upper portion of the pillar-shaped insulating layer, a lower electrode formed around a lower portion of the pillar-shaped insulating layer and connected to the resistance-changing film, a reset gate insulating film that surrounds the resistance-changing film, and a reset gate that surrounds the reset gate insulating film.