To provide a quick screw driver which can screw the screw and nut by the same operation as a general hand driver easily and efficiently.

The screwing in a low torque rotation area before the screw tightening up is carried out by turning a finger grip 1 with a finger and outputting this rotation to the bit 7 by increasing the speed by the speed increase device using the planet gear mechanism 3 in a driver main body 2 and efficiently. The screwing requiring a big tightening torque at the screw tightening up time is carried out by turning the hand grip 12 with a hand and transmitting the added force itself to the bit.