A laundry treatment apparatus in which as an outer tub vibrates, a piston and a cylinder are relatively moved. When as the outer tub vibrates, the piston and the cylinder move relative to each other and a frictional member provides a frictional force between itself and the other one to attenuate vertical vibration of the outer tub. In particular, the piston and the cylinder are prevented from being separated from each other in the laundry treatment apparatus.