The present invention relates to a skin treatment device including a handpiece and a needle tip enabling to be coupled to the handpiece, wherein as the needle tip is mounted on the distal end of the handpiece, electrical connection with the handpiece can be made stably, and even if the needle module built in the needle tip performs linear reciprocating motions of extension and retraction by the driving device provided in the handpiece, the motion trackable connector provided in the needle tip can stably keep the electrical connection between the handpiece and the needle tip.