The present invention relates to a hand piece having a low-vibration structure rotatable at a high speed. The hand piece includes a case unit having first to third cases each formed in a cylindrical shape to be held with a hand and sequentially coupled to each other from a back to a front thereof； a supply unit connected to a rear portion of the case unit to supply current, air and water to the case unit； a motor provided in the case unit to receive the current from the supply unit and generate torque, wherein the motor includes a rotor having a cylindrical shape, a connecting shaft extending forwardly of the rotor in front of the rotor and integrally formed on the rotor, a cylindrical core formed to surround the rotor while being spaced apart from an outer circumference of the rotor, a plurality of through-holes formed at an inside spaced apart from an outer circumference of the core by longitudinally penetrating the core, and a plurality of supply pipes coupled into the through holes to receive air and water from the supply unit； a collet chuck inserted into an inside of the connecting shaft in front of the connecting shaft of the motor； support members provided to the front and back of the motor inside the case, and each having bearings which is fittingly coupled to the rotator or the motor such that the rotator is shaft-rotated, wherein each of the support members has a plurality of through-holes which surrounds an outer periphery surface of each bearing and is formed at an outer side of the bearing, and the supply pipes of the motor are inserted into the through-holes； and a cover formed in front of the third case of the case unit in a cylindrical shape and having a chuck hole formed from the front thereof to the back thereof corresponding to the connecting shaft of the motor.본 발명은 고속회전이 가능한 저진동 구조를 갖는 핸드피스에 관한 것으로 손으로 파지 가능하도록 각각 원통형으로 형성되어 후방에서 전방으로 순차적으로 결합되는 제1케이스, 제2케이스 및 제3케이스를 갖는 케이스부와, 상기 케이스부의 제1케이스 후방에 연결되어 전류, 에어 및 워터를 케이스부로 공급하는 공급부와, 상기 케이스부의 내측에 공
