There is provided a method of manufacturing a Fin Field Effect Transistor (FinFET). The method may include: forming a fin on a semiconductor substrate; forming a dummy device including a dummy gate on the fin; forming an interlayer dielectric layer to cover regions except for the dummy gate; removing the dummy gate to form an opening; implanting ions to form a Punch-Through-Stop Layer (PTSL) in a portion of the fin directly under the opening, while forming reflection doped layers in portions of the fin on inner sides of source/drain regions; and forming a replacement gate in the opening.