A vertical field effect transistor is provided as follows. A substrate has a lower drain and a lower source arranged along a first direction in parallel to an upper surface of the substrate. A fin structure is disposed on the substrate and extended vertically from the upper surface of the substrate. The fin structure includes a first end portion and a second end portion arranged along the first direction. A bottom surface of a first end portion of the fin structure and a bottom surface of a second end portion of the fin structure overlap the lower drain and the lower source, respectively. The fin structure includes a sidewall having a lower sidewall region, a center sidewall region and an upper sidewall region. A gate electrode surrounds the center side sidewall region of the fin structure.