The present invention relates to a surgical instrument utilizing ultrasonic waves, the surgical instrument comprising: a transmitting rod having a cylindrical bar shape so as to transmit ultrasonic waves generated in a vibrator connected at one end of the transmitting rod to an amputator extending from the other end a rod cover covering the transmitting rod with a separating distance from the outer circumferential surface thereof and a contact prevention unit, provided on the inner circumferential surface of the rod cover, for preventing the transmitting rod from coming into contact with the rod cover due to the vibration generated on the transmitting rod during the transmission of the ultrasonic waves.
