A vertical nanowire semiconductor device manufactured by a method of manufacturing a vertical nanowire semiconductor device is provided. The vertical nanowire semiconductor device includes a substrate, a first conductive layer in a source or drain area formed above the substrate, a semiconductor nanowire of a channel area vertically upright with respect to the substrate on the first conductive layer, wherein a crystal structure thereof is grown in orientation, a second conductive layer of a drain or source area provided on the top of the semiconductor nanowire, a metal layer on the second conductive layer, a NiSi2 contact layer between the second conductive layer and the metal layer, a gate surrounding the channel area of the vertical nanowire, and a gate insulating layer located between the channel area and the gate.