A semiconductor device includes a pillar-shaped semiconductor having an impurity concentration of 1017 cm−3 or less. A first insulator surrounds the pillar-shaped semiconductor and a first metal surrounds a portion of the first insulator at a first end of the pillar-shaped semiconductor. A second metal surrounds a portion of the first insulator at a second end of the pillar-shaped semiconductor, and a third metal surrounds a portion of the first insulator in a region between the first and second metals. The first metal and the second metal are electrically insulated from the third metal. Source/drain regions are defined in the pillar-shaped semiconductor due to a work function difference between the pillar-shaped semiconductor and the first and second metals.