To provide a multifunctional variable speed type driver that is free from shaft wobbling during an operation of fastening a thread, has two or more rotation modes, and has a reduced number of components as small as possible.

The variable speed type driver includes: a grip 3; a driver shaft 2 in which an output gear 5 is fixed to the base end side, and that is supported by the grip 3 rotatably about the shaft thereof while whose tip is projected from one end side of the grip 3; a transmission gear 7 engaged with the output gear 5; a transmission gear 9 connected with a shaft 8 so as to be rotatable integrally with the transmission gear 7; a lock mechanism 11 for locking so as to regulate the rotation of the transmission gear 9 relative to the grip 3; a handle 4 movable in an axial direction of the driver shaft 2 and supported on the other end side of the grip 3 rotatably about the shaft center of the driver shaft 2; and an input gear with a diameter different from that of the transmission gear 9 which is fixed at an end of a shaft 4a of the handle 4 for releasing the lock of the transmission gear 9 caused by the lock mechanism 11 and engaged with the transmission gear 9 accompanied by the movement of the handle 4 on the grip 3 side, and also released from the engagement state with the transmission gear 9 accompanied by the movement on the side opposed to the grip 3 side.