Provided are a semiconductor device and a fabrication method thereof. The semiconductor device may include a fin-shaped active pattern and a gate electrode provided on a substrate, first and second spacers provided on a sidewall of the gate electrode, impurity regions provided at both sides of the gate electrode, a contact plug electrically connected to one of the impurity regions, and a third spacer enclosing the contact plug and having a top surface positioned at substantially the same level as a top surface of the contact plug.