A device for fixing an endotracheal tube. The device includes a body having an insertion hole, an upper wing provided on a periphery of the body and a lower wing provided on the periphery of the body that is spaced from the upper wing such that a patient’s teeth are accommodated between the lower wing and the upper wing. The device also includes a cap for accommodating a portion of the body. The device fixes the endotracheal tube firmly so that it secures the endotracheal tube when surgery is being performed on a patient in a prone position. The device is movable along the teeth so that it allows surgery on the interior of the mouth or the tonsils to be performed more efficiently. The present invention may further comprise a tooth-protection element so as to protect a tooth during a surgical operation.