<p>A screw fastener comprises a driver capable of making the rotation position of a bit to the original position and an automatic alignment device having a rotating means (164) for so rotating a screw (10) that the recess (12) is aligned in the direction along which the bit positioned at the original position is inserted into the recess without rotation and engaged therewith. The screw fastener picks up the screw from a storage part in which screws are stored, and secures a part to an object to be fastened by means of the screw. The screw fastener is characterized in that the bit and the recess (12) are respectively aligned before picking up the screw and the bit is inserted into the recess (12) without rotation and engaged therewith.</p>
