Abstract: A beauty treatment device comprising a device body, a drive unit housed in the device body, an actuator reciprocated by the drive unit, a patter, or patter assembly removably fitted to the actuator, a space guide fitted to the device body to control the reciprocating motion of the patter assembly, and a resilient member fitted to either or both of the patter assembly and the actuator, compressed as the patter advances towards the open end of the space guide and pats a skin surface being patted, wherein the reciprocating patter repeatedly pats the skin surface at a given rate, whereby removing subcutaneous fat and stimulating subcutaneous muscular tissues to prevent the skin surface to be loosened.