A laundry treatment apparatus includes a casing; an outer tub disposed in the casing; and a horizontal vibration buffering device coupling the outer tub with the casing. The horizontal vibration buffering device includes a casing connecting part coupled to the casing; an outer tub connecting part coupled to an side surface of the outer tub and having a displacement relative the casing connecting part as the outer tub vibrates; and a damper providing an attenuation force corresponding to the displacement of the outer tub connecting part relative the casing connecting part, and wherein the casing connecting part is positioned lower side the outer tub connecting part.