[PROBLEMS] Entire body of a driver is composed of a material which can be sterilized by an autoclave or an ultrasonic cleaner; when the driver is used in a limited space such as in a body cavity, work can be carried out efficiently without causing any trouble with a rotary work, and aspiration aberrant entry can be prevented when the driver body is dropped by mistake; ; and amount of rotation, rotation angle or rotary torque can be recognized even at the molar tooth portion.[MEANS FOR SOLVING PROBLEMS] A driver with a tail in which a metal or resin wire having proper resilient, flexible and shape restoring properties or a rope-like shaft composed of that wire is attached coaxially to a driver having a tip blade corresponding to various screw head fitting shapes of a driver handle on the side opposite to the installation side of the blade, and a rotary gauge or a digital torque sensor display is attached to the tip end of that shaft.