PURPOSE: To dispense with the necessity of driving various kinds of drivers in a working site and allow the use of one driver as plural drivers with a simple operation by one hand by providing a plurality of driver rods necessary for work in a bushing.

CONSTITUTION: Among a plurality of built-in driver rods 1, 11, the end part opposite to the extended shaft 3 (or 31) of a required driver rod 1 (or 11) is axially pushed toward the top end of a bushing 12, whereby a required driver bit 2 (or 21) is fixed in a position protruded from the funnel-shaped hole 11 of the bushing 12. Thereafter, it is used as the driver of a required kind by rotating the bushing 12. When the driver bit 21 (or 2) of the different kind is required, then, the end part opposite to the extended shaft 31 (or 3) of the corresponding driver rod 11 (or 1) is axially pushed toward the top end, whereby the used driver rod 1 (or 11) is changed to the driver rod 11 (or 1) provided with the required driver bit 21 (or 2).