An electrosurgical instrument used in electrosurgery, and includes a handpiece to be gripped by a user and provided with an accommodation space therein； a cable coupled to a rear end of the handpiece so as to transmit electrical energy； a conductive electrode, at least a portion of which protrudes toward a front side of the handpiece and which is configured to move in a front-rear direction relative to the handpiece； and a connecting body provided in the accommodation space and including a conductor electrically connecting the cable and the conductive electrode to each other, and a film formed of a non-conductive material and bonded to opposite sides of the conductor so as to shield the conductor, wherein at least a portion of the connecting body is formed of a Flexible Printed Circuit Board (FPCB) and is formed in a spiral or helical shape such that the total length of the connecting body is variable in the front-rear direction. According to the present disclosure, it is possible to provide an electrosurgical instrument in which, since the connecting body is provided, an electrically stable coupling state can be ensured and the conductive electrode can be moved smoothly when the conductive electrode is moved in the front-rear direction relative to the handpiece or is rotated.
