In a fin field effect transistor (Fin FET) and a method of manufacturing the Fin FET, the Fin FET includes an active pattern inside which insulating layer patterns are formed, an isolation layer pattern enclosing a sidewall of the active pattern such that an opening exposing a sidewall of the active pattern located between the insulating layer patterns is formed, a gate electrode formed on the active pattern to fill the opening, impurity regions formed at portions of the active pattern adjacent to sidewalls of the gate electrode, an insulating interlayer covering the active pattern and the gate electrode and contact plugs formed through portions of the insulating interlayer and the active pattern adjacent to the sidewalls of the gate electrode such that the contact plug makes contact with the impurity region.