PURPOSE: To simplify the structure, to make the action reliable and to aim at miniaturization by pivotally mounting a pair of jaw pipes opposite to each other on the extension of the central line of the top end of a drive at a catcher body swingably so as to make the top end thereof abut each other and further urging it by a guide spring.

CONSTITUTION: When joe pipes the top ends of which are abutted each other are positioned on the central line of a driver bit, a screw supplied from a parts supplyer is passed through a pipe 4 via hose fittings 10 and held by the top end of a parts holding portion under a state that its leg portion 20a is ahead. Next, a driver portion B and catcher A are moved forward by a start signal and the catcher A is moved forward just before its top end abuts to a work 21. At this time, the bit starts to move forward with turning, the bit 2 is moved to a position where the head 20b of a screw held at a pipe 4 is abutted, the screw 20 is screwed in the work 21, simultaneously, the top ends of the pipes 4, 4 are pushed aside, a bit 21 is projected and the screw fastening operation is completed. Accordingly, the parts holding portion is small and the fastener parts can be fastened reliably.