Fastening tool

The invention provides a fastening tool which can control the moving speed of a screwdriver bit through the movement of the screwdriver bit in the direction of fastening a screw. A fastening tool (1) is provided with: a bit holding section (3) that detachably holds a screwdriver bit (2) and is rotatable in the circumferential direction of the screwdriver bit (2) and movable in the axial direction; a bit rotation motor (40) that rotates the bit holder (3); a bit movement motor (50) that moves the bit holding part (3) in the axial direction; and a control unit (100) that controls the position of the bit holding unit (3) in the axial direction by the number of revolutions of the bit moving motor (50), and that performs control such that the moving speed of the bit holding unit (3), which is moved by the rotation of the bit moving motor (50), follows the moving speed when the screw is moved by fastening the screw to the object to be fastened by the rotation of the bit rotating motor (40). 提供一种紧固工具，能够通过使螺丝批头向紧固螺钉的